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Topic: pulling engine and GT40P heads (Read 270 times) previous topic - next topic

pulling engine and GT40P heads

Alright guys.  Here we go, gonna prob have lots of questions as I go.

I got a set of used GT40P heads, unknown mileage, pulled from yard.

I will be putting them in my 88 cougar. (stock block with 122K miles on it)  I am going to pull the engine to address a bad rear main seal leaking.

I will be adding a HO cam also, along with the Explorer upper and lower intakes.

I'm trying to get this car back into daily driver status with a little more power.

Money is very tight on this project.  I plan on getting either Alex's springs or the TrickFlow kit.  Any advise on that?

What is the bare minimum I need to do with the heads?  Can I skip a valve job and magnaflux??  Put new brass blockoff plugs or  leave alone?  I plan to just use the stock rocker arms, (Cougar,Mustang or Explorer) or does it matter??

Will my stock Cougar pushrods work?

Can I reuse my Cougar valve lifters?

I plan on putting a new oil pump in block while out.  What else?

Do I buy head gaskets based on the block or the heads?

I know a lot of questions, just trying to get parts budget and figure things out, and need your guys help.  Thanks.
Mike

Re: pulling engine and GT40P heads

Reply #1
Can I pull this off with Speed Density and 19lbers?
Mike

Re: pulling engine and GT40P heads

Reply #2
It should run ok with the stock HO cam, 19lb injectors, and speed density. The 19s are probably going to be on the edge as far as duty cycle goes (~80-85% is ideal, you'll probably be in the 90%+ range at WOT).

As far as heads go I'd want them checked by a machine shop for cracks and flatness. A valve job would also be a good idea.

On the bottom end a new oil pump (standard volume is fine) and ARP oil pump driveshaft would be all I would do.

When you swap the cams use a new, good quality double roller timing set. I'd use new lifters as well, but if the old ones are in good shape they can be reused. Check them for flat spots and stuck rollers.

Either head spring kit should work. You're going to want to check piston to valve clearance with the stock 5.0 SO pistons. It should be ok but you'd want to check to be sure.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

Re: pulling engine and GT40P heads

Reply #3
Thank you. 

What about pushrods?   My Cougar ones or do I need stock  Mustang ones?
Mike

Re: pulling engine and GT40P heads

Reply #4
If you're going to keep the stock rocker ratio, they should be alright. Pretty sure all of the roller 5.0 used the same pushrod, except for maybe the Cobra engine.

As Lou suggested, check the PtV clearance (clay), just to be certain you're not going to mess stuff up.

If you're going to run an HO cam and nothing with more lift, you ought top be ok, but again, a little "for sure" is worth a whole lot more than "I wished I had"...

;)
'84 and '87 Mustangs
'98 Explorer 5.0
'06 Lexus
'06 Explorer EB 4.6

Re: pulling engine and GT40P heads

Reply #5
Thank you. 

What about pushrods?   My Cougar ones or do I need stock  Mustang ones?

The stock pushrods should work ok. Are you using the stock rocker arms or going with roller rockers? Either way as long as they are the factory style pedestal mount rockers the stock pushrods should be fairly close. If they are slightly too long you can purchase a shim kit to adjust them.

Now if you're going to stud mount rockers then the stock pushrods will not work. You'll need hardened pushrods in that case.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

Re: pulling engine and GT40P heads

Reply #6
I would suggest putting a new timing chain on the car.  Make sure it doesn't have nylon coated teeth.
1988 Thunderbird TC, 5spd
Stinger single exhaust, Cone Filter, Adjustable Cam Pulley, Ranger roller cam conversion,
'93 Mustang Cobra replica wheels on 235/50R17

'16 F150 XLT 5.0
'17 Husqvarna TX300

Re: pulling engine and GT40P heads

Reply #7
I plan to use the stock rocker arms for now, just due to money.

Does it matter which ones?  I have my Cougar ones from the E6 heads or the stock ones on the Explorer heads??
Mike

Re: pulling engine and GT40P heads

Reply #8
I plan to use the stock rocker arms for now, just due to money.

Does it matter which ones?  I have my Cougar ones from the E6 heads or the stock ones on the Explorer heads??

They should both be the same. Try and keep them with the same fulcrum if you can. The stock sled type rockers kinda wear together over time.

As far gaskets go your best bet for intake gaskets is this set: https://www.summitracing.com/parts/fel-ms95952

And head gaskets this set: https://www.summitracing.com/parts/fel-9333pt-1
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

Re: pulling engine and GT40P heads

Reply #9
Thank you!

Can I reuse the head bolts, or spring for ARP bolts?
Mike

Re: pulling engine and GT40P heads

Reply #10
You should be able to reuse the head bolts from your Cougar without issue, just clean up the threads. Remember the bottom bolts go into a cooling jacket so they will need thread sealer.

You can't use the head bolts from the Explorer you pulled the heads from. 1993 and up 5.0s have torque to yield head bolts, which are one time use.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

Re: pulling engine and GT40P heads

Reply #11
Thank you!  I'm sure ill have a jillion more questions.  :crazy:
Mike

Re: pulling engine and GT40P heads

Reply #12
No problem. Have fun and take your time.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.