Should be real smooth in a 351 W engine.
Its a better fit in a 289 engine.
I would urge you to check into a custom ground cam.(usually the same price than an off  the shelf grind).
With stock exhaust manifolds I would want a little more duration on the exhaust side to give the exhaust a little more time to get cleared out of the chamber.
6s6

I do believe talking your combination over with a couple of the tech guys at cam companies. However,  the stock M code 351w had 10.7 cr with iron heads, and the 2v H code had 9.5 cr.

I have a comp cams 268xe flat tappet in my 351w, stroked to 393. While I do have an extra ~42 inches on the stroke, and many folks think the 268 is small, I am happy with it and have enough torque to make driving with 2.50 rear gears when I had the fmx, a non issue.

I would not discount your engine builders recommendation. Just be thankful his name isn't 6sally6!

rpm wrote:

I do believe talking your combination over with a couple of the tech guys at cam companies. However, the stock M code 351w had 10.7 cr with iron heads, and the 2v H code had 9.5 cr.

Yes, but that was when 100+ octane leaded fuel was available at every gas station.  Now you are lucky to find 93 octane.  Also, those were the manufacturer's claimed numbers.  I've always found those to be rather optimistic.  Typically I've found when measuring that they are at least 0.5 point lower than stated. 

A lumpy cam can cheat the number by bleeding off compression at lower RPM due to increased overlap.  If the plan was a street/strip car on a budget I'd say go ahead and go that route, but his plan's the exact opposite of that.  You are going to want a cam that has very little overlap, and is going to bolster low speed compression as a result.  Its the difference between static and dynamic compression.  I've built a lot of iron headed truck and boat engines for low end grunt and I learned quick not to go past 9:1 with iron heads and a cam designed for low end torque, and a lot of the BBCs I built ran great at only 8.5:1.  If he had EFI he could probably get away with it, but I wouldn't chance it with a carb. 
 

I fully agree with the others on talking to several cam companies. I’ve never dealt with Comp Cams, I’m sure they make good cams but they are not the only company making cams. They spend a lot on advertising. The one complaint I hear about them is when you call for tech advice, they’re pretty much reading off a scripted flow chart. A couple years back I was thinking about a cam and called Howard’s Cams. Great people. I spoke with several techs, all were friendly and spoke 1 on 1 with you. I hear Isky is the same way. Definitely at a minimum talk to several cam companies to get free advice for the right cam. A custom ground is even better.

The other issue I have are the stock heads. The 289 heads are a restriction on a 289 due to the exhaust port. The early 351W heads despite having larger intake port and larger intake and exhaust valves, has the same size exhaust port as a 289. Even with the larger 1.54” vs 1.45” valve, it doesn’t flow any better on the exhaust then a 289 head.

I would step back for a moment and think about different heads possibly. I would think about something like a GT40 head. Bigger exhaust port and bigger combustion chamber. They will flow better and lower the CR to something more friendly. The down side is the cost to rebuild them as well as the stock heads with a little port work may very well put you close if not in to a set of aluminum heads. Something like the Edelbrock E Street heads. They’re more of a budget friendly head that makes more power then stock heads for about the price of rebuilt stock heads.

Once you have better flowing heads, you can use a milder cam to meet your power goals with better characteristics

TKOPerformance wrote:

I considered giving Comp a shot at my last cam.  I couldn't get anyone on the phone and they took a week to respond to my email.  I had the cam from Crane by the time they bothered to reply to my email.  Frankly that's all I need to know.  If it ain't broke, don't fix it, and I'll be sticking with Crane from here on out unless something changes. 

That's interesting on the 351 heads Huskinhano.  I used to hear about guys searching high and low for 351 heads to put on their 5.0s.  It made no sense to me that a 20 year old head design was going to be better than a modern performance head, or even the E7TE heads they had stock.  This was in the late '80s, early '90s too.  Before aluminum heads were cheap and everyone used them.  Today, unless there are racing class rules, its a restoration, or the budget is super, super tight (no porting, etc.) I see no reason to reuse iron heads of any generation.  It initially seems cheap, but once you start adding up all the costs you hit that $1,000 mark pretty quick, and there are several aluminum aftermarket options out there for $1,000 that are going to be better than most sets of worked over iron heads. 

Yeah, google flow charts on SBF heads or comparisons. The reason 351W became popular is simple, it WAS the only other option. The other thing, back in the day intake port size on aftermarket intakes were more or less sized to the 289/302 head. So the intake would still be a restriction. The old Torker everyone loves would be a restriction on today’s heads.

As far as stock factory sbf heads go, the P heads are my favorite. If, you have a good set that doesn’t need rebuilding and you can work around the plug angle, I think the the P heads can work out very well for a small budget. I wouldn’t dump a lot of money in them mostly because like any other factory head, you’re going to have a lot of money invested

This guy was running a stock GT40P longblock with 100k miles and the heads were never off. He’s using a custom ground cam and I’m sure lots of tuning but still.

https://m.youtube.com/watch?v=-X66KA_jfMI

The P heads should be the best.  They were the last evolution before 5.0 production ceased in favor of the modular based engines.  Great port design.  The GT 40 was a great design for its day.  One of my good friends has a '95 Cobra with a 306 DSS shortblock topped with the stock GT40 heads (worked over of course) and topped with a Kenne Belle blower.  That car is ridiculous.  In 3rd gear at 60MPH if you floor it the tires break loose.  He leaves probably 150-200HP on the table with the street tune he runs because otherwise its just totally unmanageable on the street. 

The limitation with even the best of the stock heads is the same as those of any make/model.  They weren't designed for much more power than what the engine they came on made stock.  The valvesprings won't tolerate a big cam.  Low lift flow is great, but go much past 0.500 lift and they stop flowing well.  This was the problem with the GM Vortec heads and I'd presume the Mopar Magnum heads too.  If you were a machinist by trade and could eliminate most of the costs of modifying them then its a different story, and its not that they can't be made to work well; its purely cost.  The biggest thing now is finding a decent set, because the newest ones are probably 15 years old.  I heard the production GT40s had a problem with cracking, not sure if this affected the P heads too.  Vehicles sitting outside in wrecking yards can have the coolant freeze, etc.  Not a problem in some areas of the country, but it sure is around here.  Like anything else you've just got to be smart about what you buy.  Any engine build is expensive to some degree for most of us, but when you end up having to buy things twice it really starts to get out of hand.