I intend to mostly use it cruising around, and having fun, not thinking about racing the car or anything. I would like to be able to feel some g-forces when I get into the accelerator though, maybe scare myself once in a while.... but truthfully I think  it will mostly be used for all around travel, longer road trips, hitting some curvy pavement, not really a daily driver.

  The builder said he is going to tear it down and inspect the crank, and then we can go from there, he also stated he always puts in new pistons/rings, I brought up the idea of boring it over. I would like to add a cam, and headers, and I have been looking into possibly some aluminum heads as well but on the fence, in my reading it seems that the stock 5.0 heads have a bit of restriction but maybe that's mostly to folks that want "high-end" performance not a primarily street driven car?

MS is 100% correct, you are safe with a 0.030" overbore, maybe a 0.040", and dicey at 0.060".  The newer engines like the 5.0 were made in an era where they had gotten much better at reducing core shift, which allowed manufacturer's to cast thinner wall castings.  Good for weight reduction, bad for longevity.  I remember reading about a 352 FE engine a guy bored 0.125" to get a standard bore 428.  He had the block sonic checked prior to boring it to ensure that it could take that much of an overbore, but it checked out okay.  That's 1/8"!  BTW, you could sonic check the block to see how much it could be bored, but the cost for the testing is likely not justified on an engine where you can buy a brand new fully machined block for about $500, let alone the cost of a good used one.

So, a 0.030" overbore on a 5.0/302 is going to yield a 4.030" bore with a 3" stroke for a total of 306 cubic inches.  To go much bigger than that you are going to have to stroke the engine.  Think of it this way, boring an engine changes the volume of the cylinder a small amount, stroking it changes it a large amount, because you can make radical changes to stroke length (relatively speaking).  So to get to 347 cubic inches you bore the engine 0.030" and install a crank with a stroke of 3.400" instead of the stock 5.0/302 stroke of 3.000".

Now this isn't as simple as it sounds.  You are going to have to clearance the block to prevent interference between the rods and the casting.  You are also going to have to run pistons designed for the stroker, as regular 5.0/302 pistons would have the piston sticking way out of the block at TDC.  The best method is just to buy a stroker kit with crank, rods, pistons, rings, and bearings.  Often you can get them already balanced too.  This is the safest route, as you know all the parts work together.  So long as you use aftermarket style rods with capscrews instead of bolts you shouldn't have to worry about cam to rod bolt interference, meaning you can run a regular cam (in the old days you used to have to run reduced base circle cams to avoid hitting the rod bolts, and that was a whole other thing you had to plan for and set up). 

Now, 331 or 347?  The 331 has a shorter stroke and proponents will say less thrust loading on the pistons, plus pistons with longer skirts, and ring life is better.  The 347 is bigger, and all things being equal is going to make a bit more torque.  I'm building a 347 now.  I might have gone the 331 route, but I got a screaming deal on the engine that I could not pass up.  I look at it this way, if the rings wear out in 75k miles instead of 100k miles its not that big a deal in a car I put 2k a year on.  I've never heard of cooling issues with a properly built engine and cooling system.  I've built several strokers over the years and all have run without cooling issues.  Tire life has certainly decreased though. 

Not being well versed in engines I would advise presenting your builder with a goal and allowing him to get there how he sees fit.  Or, as MS says, there's always the crate route.  Then you are getting a known quantity.  Most street oriented engines are going to be in the 350-420HP range.  The more power typically the worse the idle quality, and the bigger the engine the less aggressive it has to be, so if a 347 and a 331 are making the same power the 347 will be a bit more tractable.  Its not going to be a tremendous difference like you'd see between a 302 and a 427, but its something else to consider.  And yes, to achieve those kinds of power you're going to have to match the heads, cam, induction, and exhaust to a common goal.  A 350HP cam is never going to make 420HP, and 500HP heads on a 350HP engine are going to run poorly.  Everything affects everything else.  Head spinning yet?

 

I always felt that the 327 bowtie had the best bore to stroke ratio ever...which produced an engine that would pull a 4000 lb Impala down the road at 70 and deliver mpg  in the 20+ range...way back in the day.  And I still feel the the 327 was one of, if not the best, over all production V8 ever.  So....a stock 302 with a  .030 over bore gives +4 ci.  Take that bore and add a 331 stroker kit and get 331 CI.  Leave the bore at stock 4.00 and you get 327. Exactly the same bore to stroke ratio as the bowtie and with a set of AFR heads and a bit of a cam it will mill of mail boxes quicker that you can holler..."DON'T LIFT"!!!!

BB

A 351W will have 4 more cubic inches at its stock, standard bore than a 347 and 20 more cubic inches than a 331.

If you're wanting to build a stroker, a 351W can be stroked to various sizes: 383, 393, 408, 418, 427 and with a more expensive Ford Racing block, it could even be made into a 454.

At its stock bore, a 351W will be bigger than the biggest 302/5.0L stroker produced. In stroked form, the 351W can be anywhere from bigger than the biggest stroked 302/5.0L stroker to being way bigger. A 351W will be about the same (money-wise) to build as a stroked 302/5.0L but, the 351W will produce much more power for roughly the same amount of money spent on the stroked 302/5.0L engine.

It's just something to weigh and consider, performance vs. dollars spent, to stroke an engine and which one you'll get you the most power and bang for the buck from.

My Dos Centavos.
I took a mid 70s 302 engine to a Dallas machine shop and had them square the deck and bore it .030 over, then bought a fully balanced 347 stroker rotating assembly and had them install it into the block. I paid extra for the full balance components and recommend this if you are going stroker route. Every item from the flywheel forward has a serial number stamp and Eagle keeps this data on file.
http://www.eaglerod.com/index.php?option=com_content&task=view&id=27&Itemid=25

The grinding they did on my engine was very minimal.
From the Eagle website they talk about the Stroker engines and hork up some math.
http://www.eaglerod.com/index.php?option=com_content&task=view&id=40&Itemid=25

I like my engine, it had issues at the start that were Carb related and running too lean, but now that everything is dialed in it runs very well.

 

A stroker 331 or 347 is certainly a viable option, and properly built both can be great engines.  What you need is a clearly defined goal and budget.  Projects without these languish.  If you say the goal is 350HP (not saying it is, I picked that number based on what I gleaned from your goals) then the next question is budget.  You could probably build a 350HP 302 for $5,000 if you shop well.  A stroker is going to add $2,000 to that price, maybe more depending on the balance and materials from which the parts are made, etc.  Now, with say $8,000-$9,000 you could use all premium parts and increase your HP number.  It also depends on what you are going to buy new vs. reuse.  Stuff like a distributor, exhaust system, radiator, water pump, etc. all add up to a couple grand a lot quicker than you think.  Its nice to have some cushion on a project like this.

I will reiterate my point about a bigger engine being more docile at equivalent power.  A 350HP 347 is going to be pretty tame, nice smooth idle, and a lot of low end torque.  A 350HP 302 is going to have a lumpier idle, and power production is going to move up the RPM range, with peak power hitting right around 6,000RPM.  Its sweet spot is going to be 2,500RPM and up.  The 347 on the other hand will be making great torque right off idle.  But again, light car, not hard to get moving especially with a decent rear gear (3.50-3.73).  You may find that the 347 has a much greater chance to light the tires, and that the 302 is actually easier to drive because of the lack of low end.  A lot of this has to do with the type of driving you do, and how you drive. 

I can tell you, my WRX, which weighs 3,000lbs, right about what a classic Mustang weighs, makes right about 300HP.  It's powerband is 3,000RPM-6,500RPM.  Its a stick, and knowing how to drive it I do not miss the low end.  From 3,000RPM up it flat rips.  Its plenty fast, and on a twisty road I've hung with or beaten Z06 Corvettes, Audi S4s, and plenty of other cars costing 2-5 times as much.  I haven't run it since I finished all my mods, but it ran a 14.50 stock and a 14.20 with some mild bolts ons (and I wasn't launching well that night either, my 60' was awful).  I'm think it should be capable of 13.60s or better now.  Its actually very similar to the Fox body Mustangs, stock HP is 227 vs. 225 for the Fox.  Weight is comprable, and thus so is track performance.  The big differences are I get a much better hole shot thanks to AWD and its a turbo, so the powerband is different.  But, weight and HP pretty much dictate ET regardless of setup, so as a point of real world comparison its very valid. 

Wow lots of input, so much in fact I had to re-read it all a few times! Well let me see what boxes I can check here:

  I reckon the end goal of this motor build would have to be a reliable engine with a nice amount of "WOW" factor, whilst still retaining the ability to drive for 4-6 hours without stopping to fill the tank 5 times. Now having said this, I am not sure if that factor is found at 300/350/400 hp, guess I never defined it by HP, only by feel (probably might make some Motorheads cringe) lets just say like mentioned above that I am shooting for 350HP to put a number on it. When I re-built my rear end a little while back ( the original 8in. mind you)  I went ahead and re-geared to a 3.50 and and now glad I added the Traction-Lock/LSD(?) from yukon so maybe this will make traction a little better because whats power without traction.....right? With that, the plan has always been to mate this motor to a T-5 because I envision rowing through the gears adding to the fun, and being able to shift into 5th for 75mph freeway drives, w/o revving at 3300rpm.

 I also am not fixated with the 347 it was simply an idea I have had, I do like the idea  from BullettBob of this 327 "Bow-tie motor", seems like a great compromise of all the aforementioned things I am looking for!  Could this mean I am leaning towards something more like a 331?

Unfortunately, Yall start talking about bores, strokes, clearances, cam to rod bolt interfaces things start getting a little hazy for me, makes me wish I would have continued on with shop class in high school, but I guess its never too late to learn! Bill (the motor builder) did the same thing to me last week talking about heads, chamber sizes, tolerances and I found myself drifting away to a recent surf trip I took to hawaii, warm sand/beaches, sun in my face....

   I think I will leave some of the decision making up to him as he is the guy that has been doing this for 40 years not me, the kinda guy that has a dozen 5 gallon buckets filled with old pistons, motors everywhere (nice 383 stroker he is currently building, 454's, cummins inline 6cyl he is doing the heads on, a couple project cars in the garage, blocks everywhere) I do like to go into the decision making process with some information though so I know what I am entering into.

Lastly I have to consider budget on this build, thanks BruceB for not beating around the proverbial bush! Again, I had not really considered the numbers game, however I am not in a place to pull a MS and dump $10/$12,000  on an all aluminum screamer, but I realize I probably wont get what I have in mind for $1000.00 sheckles. In all honesty, I would like to spend as little as possible to get an amazing motor built, but dont we all. I reckon though I will set the cap somewhere right in the middle of those two figures and if I can fall below that great, or if I reach or exceed that by a bit well I am prepared to do that as well. I started this project knowing that the motor/trans were going to be my big ticket items, and the rest would just nickel and dime me to Eden, so here we go! Good thing being he is able to build it over the course a few weeks or months so I can chip away at it instead of one-lump-sum which in my mind helps me move past denial and into the acceptance stage...

  

Why not just cut for it and install a 351w?  These days it is very easy.  A little bit of cam and you can do 350hp.  Even if not you will have lots of torque down low where you will be spending 95% of your time.  Get a roller.  They were installed in mid 90's trucks. Two down sides: It is a little heavier than the 302, and it is tighter on the sides requiring easy-to-find headers.  It also has the same balance as a 289 meaning you can use a 289 flywheel/clutch just fine.

And make sure you get the close ratio T5.  The wide ratio has a 3.35 low gear, making for a useless first with that 3:50 rear end..

I built a 331 because the rod ratio was closer to 289's  ratio. We all know that the 289 had a lot of miles built into it and if cared for could roll up a lot of miles, I wanted my 331 to be able to very reliable  with no future rebuilds.
.  When my engine builder and sat down and planned out what the use for the powerplant was going to be used for we decided  longevity of the 331 was a better choice than the extra 16 cubic inches that the 347 with its poorer rod ratio.
 With an AOD and 3.25 gears I can average 22-24 MPG on a long trip cruising a 70 mph and 1950 rpm.
 I put a lot of miles on this engine and have never ever thought that I really needed those extra 16 cubic inches.
 You have to build the engine for what you are going to use it for.

Last edited by Rudi (2/22/2016 4:56 PM)

devovino wrote:

Wow lots of input, so much in fact I had to re-read it all a few times! Well let me see what boxes I can check here:

  I reckon the end goal of this motor build would have to be a reliable engine with a nice amount of "WOW" factor, whilst still retaining the ability to drive for 4-6 hours without stopping to fill the tank 5 times. Now having said this, I am not sure if that factor is found at 300/350/400 hp, guess I never defined it by HP, only by feel (probably might make some Motorheads cringe) lets just say like mentioned above that I am shooting for 350HP to put a number on it. When I re-built my rear end a little while back ( the original 8in. mind you)  I went ahead and re-geared to a 3.50 and and now glad I added the Traction-Lock/LSD(?) from yukon so maybe this will make traction a little better because whats power without traction.....right? With that, the plan has always been to mate this motor to a T-5 because I envision rowing through the gears adding to the fun, and being able to shift into 5th for 75mph freeway drives, w/o revving at 3300rpm.

 I also am not fixated with the 347 it was simply an idea I have had, I do like the idea  from BullettBob of this 327 "Bow-tie motor", seems like a great compromise of all the aforementioned things I am looking for!  Could this mean I am leaning towards something more like a 331?

Unfortunately, Yall start talking about bores, strokes, clearances, cam to rod bolt interfaces things start getting a little hazy for me, makes me wish I would have continued on with shop class in high school, but I guess its never too late to learn! Bill (the motor builder) did the same thing to me last week talking about heads, chamber sizes, tolerances and I found myself drifting away to a recent surf trip I took to hawaii, warm sand/beaches, sun in my face....

   I think I will leave some of the decision making up to him as he is the guy that has been doing this for 40 years not me, the kinda guy that has a dozen 5 gallon buckets filled with old pistons, motors everywhere (nice 383 stroker he is currently building, 454's, cummins inline 6cyl he is doing the heads on, a couple project cars in the garage, blocks everywhere) I do like to go into the decision making process with some information though so I know what I am entering into.

Lastly I have to consider budget on this build, thanks BruceB for not beating around the proverbial bush! Again, I had not really considered the numbers game, however I am not in a place to pull a MS and dump $10/$12,000  on an all aluminum screamer, but I realize I probably wont get what I have in mind for $1000.00 sheckles. In all honesty, I would like to spend as little as possible to get an amazing motor built, but dont we all. I reckon though I will set the cap somewhere right in the middle of those two figures and if I can fall below that great, or if I reach or exceed that by a bit well I am prepared to do that as well. I started this project knowing that the motor/trans were going to be my big ticket items, and the rest would just nickel and dime me to Eden, so here we go! Good thing being he is able to build it over the course a few weeks or months so I can chip away at it instead of one-lump-sum which in my mind helps me move past denial and into the acceptance stage...

  

A lot of companies sell balanced stroker kits.  So if I were you and interested in saving a few bucks, I'd let the builder do the machining, you buy the parts and put the motor together yourself.  You'll have to do a bit of research and coordinating between your builder and your parts suppliers, but this isn't rocket science and judging from what I've seen you do already, this should be a snap.

I second all of TKO's posts. You and your engine builder will have a heart to heart convo about your engine. One thing you have to be brutally honest with yourself concerning your engine and power goals and what you are willing to compromise to get there. What kind of fuel do you want to run, idle quality, how are you going to drive it, hp goal ( which sounds like you are set), capable of running accessories like A/C, temperament- can you run it all day long or do you need a big radiator, etc. Depending on how much parts cost in your area and the amount of machine work needed, I think you are in the 3-5k range for 350hp out of a 302. That is depending alot on machine shop rates and procedures that need or don't need to be done on your engine.

Let me jump in here!
A331 will have an easier time making 350 HP than a 30 over 5.0. Why?!  Its bigger and not struggling to make the same number.
Now whether your engine goal is 300 or 450 is irrelevant. The larger the engine/cu. in. the easier on parts when making that number.  351's a little heavier and a little wider than the 5.0 butt starts out making 50/75 more horse power just because of its size!
Size DOES matter!
331 would be my choice for what you've said  your expectations might be.
(With a HUGE cam!!)
6s6