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1/24/2024 7:49 PM  #1

66 engine swap

It’s been a while since I’ve posted. I’m considering replacing the 289 in my 66 coupe. I have it mated to a T5. What I’m looking for are suggestion as to what engine would make a good swap. The priority is ease of installation. I’m not looking for anything high performance just a good dependable v8 that won’t break the bank. I’m leaning toward something that I can use my Edelbrock intake on.

"anyone that stops learning is old, whether at twenty or eighty"Henry Ford

1/24/2024 9:30 PM  #2

Re: 66 engine swap

A freshened up stock roller block 5.0L or a stroker of your choice for additional torque.

The intake, carb, dizzy, and Flowmaster 50's will all bolt back up.

The flywheel and harmonic balancer just need to match the engine balance.

If you keep it simple, could be a fun project for a retiree. 

Still running an open 3.55?


1/24/2024 9:35 PM  #3

Re: 66 engine swap

I built three 5.0’s this summer. Dressed up like a 289. The guys that purchased them were very happy with their 289 replacements.
Key component is factory roller cam.

Money you enjoy wasting is NOT wasted money... unless your wife finds out.

1/25/2024 6:08 AM  #4

Re: 66 engine swap

I agree.  A warmed over 5.0 makes a great sap for a 289.  How warmed over will depend on your budget.  If you are going to stick with iron hes I'd look to get an engine that has GT40 heads on it, or GT40P heads (though this might make finding headers a bit more difficult).  Another cheaper option for heads would be Edelbrock aluminum.  I would not touch anything made overseas.  AFRs are the best choice, but also the most expensive.  Trick Flow would be a middle ground.  Cammed properly such an engine would make 300-350HP pretty easily. 


1/25/2024 9:48 AM  #5

Re: 66 engine swap

I’m on a very tight budget so I’m looking at low milage used. Probably a pick n pull deal. What years/models should I be looking at.

"anyone that stops learning is old, whether at twenty or eighty"Henry Ford
     Thread Starter

1/25/2024 12:05 PM  #6

Re: 66 engine swap

I went to a local rebuilder for the short block (roller), minus the cam, timing gear and oil pump.  They were very good with working with me.  I used Edelbrock heads and intake manifold. 
Note that a roller cam setup costs more than a flat tappet cam.  

IMO - Figure out how much it will cost to do a set of heads.  I found the Edelbrock heads (I used the 60329 model) were a better investment overall. 

Last edited by BobE (1/25/2024 4:41 PM)

65 Fastback, 351W, 5-speed, 4 wheel discs, 9" rear,  R&C Front End.

1/25/2024 12:41 PM  #7

Re: 66 engine swap

My thoughts would be, what's currently done to the 289?  If its a solid running engine I think you'd be better off to make some upgrades to it vs. swapping it for a junkyard motor without rebuilding it.  I don't trust anything that comes out of a junkyard.  That vehicle ended up there for a reason, often because the last owner got tired of fixing it, couldn't figure out what was wrong with it, etc.  Sure, some were involved in wrecks and might be low mileage, etc., bot how long's it been sitting there?  The last 5.0 was installed in 2001, that's now 22 years ago (going on 23). 

Another thing to know is that the GT40 heads only came on '96-mid '97 Explorers and Mountaineers.  After that it was the GT40Ps.  The exhaust ports are raised on the P heads and standard headers probably won't fit (they don't in the Fox body cars).  There is also strict limitations on cam lift due to exhaust valve rotators.  They flow decent, but you need to do some stuff to them to make them work for anything but the mildest of performance use.  These were low RPM truck engines after all.  The more money you spend on them to closer you get to the cost of entry level aluminum heads. 

So the real question would be: how tight is the budget?  Another option is check out Craigslist, FBM, eBay, etc.  Sometimes you find decent deals.  I'd be wary of motors sold there though.  Heads, new parts, etc. are probably safe. 


1/25/2024 5:32 PM  #8

Re: 66 engine swap

I suggest a nice 427 side oiler with the dual quad set-up. May need to switch to a beefy 4 speed or ....for a little bit more go with a 5 speed Lenco.


Get busy Liv'in or get busy Die'n....Host of the 2020 Bash at the Beach/The only Bash that got cancelled  )8

1/25/2024 5:38 PM  #9

Re: 66 engine swap

No really...
.if the 289 is still good and you just want a little more  umppph....what about a stroker kit ?
The cylinder skirts are shorter on "SOME" 289 butt the stroker crank(and associated pistons  will work  (the 331 one)
I think its a 3.25 skroke.
The piston will just be at the very bottom of the cylinders.
Just this alone with whatever else you have on the 289 will prolly get you sideways in the first 2 gears !
May be cheaper than buying a crate engine or even going through a 5.0 out of the junk yard.
Food for thought............(You could make old Sal happy with a big-old snotty camshaft butt that's up to you !!!)

Get busy Liv'in or get busy Die'n....Host of the 2020 Bash at the Beach/The only Bash that got cancelled  )8

1/25/2024 6:18 PM  #10

Re: 66 engine swap


Get busy Liv'in or get busy Die'n....Host of the 2020 Bash at the Beach/The only Bash that got cancelled  )8

1/26/2024 7:55 AM  #11

Re: 66 engine swap

The downsides to building a 289 is the potentially shorter cylinder skirts (not sure how you would know that prior to a teardown) AND lack of a factory roller cam.  Cost wise you can probably go through a whole 5.0 and refresh it for the cost of a stroker kit and install in a 289, AND the big issue is that the stock heads will be inadequate for the bottom end now.  Assuming GT40s or GT40Ps they work great on a 302.  Going bigger you would really need to port/rework them, at that point you're bucks ahead to buy a set of Edelbrocks.

I considered stroking my existing 289, but decided to go with a 5.0 based stroker instead for the reasons mentioned.  I always assumed I was buying heads, so all things basically being equal I saved considerable money with the factory roller setup

This is how projects get out of hand, especially from a cost standpoint.  Your cheapest option would be to just add a cam, headers, intake, and tune the carb and distributor in the existing 289.  Heck, you could add a set of heads to that list and still be under the cost of an engine swap.  After that its probably a fresh 5.0 with GT40 heads and a better cam.  Then a 5.0 with cam and heads.  On a tight budget I think I'd stick with stock displacement bored as needed to get clean, straight cylinders (302 might become a 306 due to an over bore, etc.).  Strokers need clearancing, balancing, and you may need a new balancer & flywheel. 


1/26/2024 1:43 PM  #12

Re: 66 engine swap

One thing to watch for with a different engine.  If you are running a stick shift with Z-bar clutch linkage:  The 289 block has a bung on it to mount the linkage.  later blocks may not have one.  It can be very frustrating to discover that condition after the engine is installed and you are hooking up the clutch.  Fortunately, there is a fixture you can buy that solves that problem.  It bolts up to the block. No special tools.  Most any Mustang supply house will have one.

Original owner - 351w,T-5, 4whl disks, power R&P

1/26/2024 1:57 PM  #13

Re: 66 engine swap

That clutch linkage boss was broken off the  5.0 block I used for my 331 build. My local engine builder had no use for it and gave it to me free, he did change for decking, line bore cylinder bore etc. though.
My AOD did not need it.
Scrounging around may get you lucky as well.

Good work ain't cheap, Cheap work ain't good!   Simple Man

1/28/2024 4:31 PM  #14

Re: 66 engine swap

96-97 Explorer
I have built several. Never seen one with more than 0.0005 cylinder wear. (That is 1/2 of one thousandth of an inch.
Cranks usually look like new.
Hone it and stick it back together with a little bigger cam

They have GT40 heads with 1.84 intake valves. Mill heads 0.030 for higher compression. New valve springs and valve job.  Or, sell the heads and buy some quality aluminum ones.

Throw away everything except block, crank, rods, pistons and heads.
Replace it with the 289 stuff, except flywheel and balancer, get from summit, for 50 ounce but fits the 289 size requirements.
Distributor with steel gear for billet roller cam (1985 Mustang Duraspark or a pertronix 3 stock apearance

Money you enjoy wasting is NOT wasted money... unless your wife finds out.

Board footera

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