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Topic: Talking cylinder heads. (Read 5319 times) previous topic - next topic

Talking cylinder heads.

Hey everyone. I know that the stock heads on the 5.0 birds are either e6 or e7 which we all know are restrictive. Now in order to get more power those either have to be ported or buy aftermarket heads. Now I have a set of gt40p heads that I might throw on sometime soon but idk of I should wait and sell those heads and get some aluminum ones would it be worth the wait? Or are there other heads that would fit with the stock pistons that offer a bigger power gain?
Of you have any info please comment on this thread Thanks!!!

Talking cylinder heads.

Reply #1
The P heads will make some really good power but it depends on cam, intake, and compression ratio your short block already has.  We really need to know what the short block came out of and if it is stock or what you have changed to make any kind of a real suggestion here.

Darren

83 351W TKO'd T-Bird on the bottle


93 331 Mustang Coupe - 368 rwhp

Talking cylinder heads.

Reply #2
Well it's a thunderbird sport so it came with the 5.0 from the factory. It's 100% stock accept for the exhaust system because I am planning on doing some intake modifications.

Talking cylinder heads.

Reply #3
So the short block will stay the same and you would install the P heads?  Would you be installing an Explorer intake or similar with a larger throttle body?  I only ask as the P heads should be a huge improvement over the stock heads but if you do not compliment them with a decent intake and throttle body they will choke the heads a little bit.  Still I would say swap the heads even if that is the only thing you are going to do as it will improve the performance.  If you can swing it do the heads, upper & lower intakes, and throttle body as that will be a substantial change but the only thing I am not sure about is if the SD EEC will support it but I don't see why it would not.  The thing to do after that is to convert it to mass air, change the injectors to match the MAF, and then ask around about camshaft selection with the pistons that are in the motor.  When you tear the motor down to install the heads make a note if the pistons have valve reliefs (take a few pictures) as that will help a lot with knowing a range of camshafts that will work with them.  Also, don't forget to get a good double roller timing chain.

One thing you should do is have the heads checked to see if they need a valve job and install new springs.  Just make sure you do not put too much spring on them for the stock cam but ones that will work with a roller cam at a later date.

Darren

83 351W TKO'd T-Bird on the bottle


93 331 Mustang Coupe - 368 rwhp

Talking cylinder heads.

Reply #4
Im going to get the heads resurfaced and im going to put some edelbrock 1.6 roller rockers on it and probably some mild springs. i was planning on doing the HO conversion and the head swap at the same time just so i have a big enough cam like you said. I was also planning on putting a cobra intake on. I want to go up to atleast 350hp and im sure those gt heads can handle it.

Talking cylinder heads.

Reply #5
Sounds like you have a good plan then.  The only thing I will say is 350 hp is a pretty lofty goal for that combination.  I would guess that 250 rwhp would be reasonable goal with torque in the 280 to 290 ft-lbs.  That will motivate the Bird very well.

Darren

83 351W TKO'd T-Bird on the bottle


93 331 Mustang Coupe - 368 rwhp

Talking cylinder heads.

Reply #6
If you are getting the heads resurfaced why don't you just get a ready to run new set of aluminum ones? $699 will get you a decent set with nothing required other than bolting them in. You can grow into the aluminum heads where you can outgrow the gt40s if you get the modding bug, and trust me it happens. If you aren't rebuilding the heads yourself or got em free the gt40s could end up costing as much as aluminum heads after new valve seals, springs, valves, and all the machine to work to fit the new valves. I don't know just seems silly to me, it is like trading your oxe for a donkey when you could be getting a horse for the same money.

Talking cylinder heads.

Reply #7
Locate a good used 87-93 HO roller block and add a set of mike's heads and some headers. ALL parts go together without a problem and make a nice package.
http://www.hunterstyle.com/thumper/combos.php
84 COUGAR/90 HO, 1.7RRs, performer RPM,700DP, equal length shorties, stainless EXH ,T-5,Hurst pro-billet, KC clutch, 8.8/ 4.10s, line-lok, bla ,bla, bla.
71 COMET/289,351w heads, 12.5 TRWs, 750DP, Liberty TL, 9"/6.00s, 11.9x @112 , bla,bla,bla.

Never shoot your mouth off, unless your brain is loaded! ....I may get older, but I'll never grow up!....If you're not laughing, you're not living!  :laughing:

Talking cylinder heads.

Reply #8
Guys, he has an existing 5.0 in his car and already has the P heads and intake. What you are suggesting would be going backwards and spending quite a bit of money.

Darren

83 351W TKO'd T-Bird on the bottle


93 331 Mustang Coupe - 368 rwhp

Talking cylinder heads.

Reply #9
On the cheap, the heads will work fine but I'd check them out before installation. Check the springs, seats, guides, clearances, etc. If they're alright and you don't plan on heading over 4500-5000rpms, they'll be fine for awhile, until you get the urge for more.

If you had to spend over $200 in machine work (valve/seat work) or parts, other than stem seals, I'd go with some aluminum heads. I've seen some nice deals on reworked gt40y and x heads for just over $500.

If the heads are good enough, on the cheap I'd just lap the valves, replace the valve stem seals, pick up an explorer intake, and an HO cam. With the stock AOD with the tv cable setup to provide more pressure, you'd be looking at closer to 4500rpm shifts and it'd be much more powerful. You can do exhaust, throttle body, etc as funds allow. A good flowing unported gt40/gt40p setup should get you over 300hp, maybe around 320 tops if spun to 5k. It can be some of the cheapest power you can make. Going for another 60-100hp in the 302 can easily triple the price for only 20-25% more power. If you were to just bolt on the heads with a HO intake and cam, without exhaust work or anything, I'd expect like 230hp at best. The stock exhaust on these cars is extremely restrictive, as will the be the HO intake. The thing is, the heads are still more efficient and you can grow into them by upgrading the intake and exhaust.

So what is the budget, and what are your reasonable expectations?
1988 Thunderbird Sport

Talking cylinder heads.

Reply #10
Quote from: Aerocoupe;411969
Guys, he has an existing 5.0 in his car and already has the P heads and intake. What you are suggesting would be going backwards and spending quite a bit of money.

Darren
....which 5.0?  A roller block has forged pistons, HO cam and add a set of 1.7 RR to his or other heads makes for a dependable ride. Heads are useless unless there is something decent that they are bolted to. Just my opinion.
84 COUGAR/90 HO, 1.7RRs, performer RPM,700DP, equal length shorties, stainless EXH ,T-5,Hurst pro-billet, KC clutch, 8.8/ 4.10s, line-lok, bla ,bla, bla.
71 COMET/289,351w heads, 12.5 TRWs, 750DP, Liberty TL, 9"/6.00s, 11.9x @112 , bla,bla,bla.

Never shoot your mouth off, unless your brain is loaded! ....I may get older, but I'll never grow up!....If you're not laughing, you're not living!  :laughing:

Talking cylinder heads.

Reply #11
OK, if you got the heads already and they DON'T need work then it is worth it, if you gotta machine em or do anything to em, then it is NOT worth it.

Here is an example, I bought a set of SBC Dart iron eagle race heads for the 400 small block that is going in my s10. They were supposed to be ready to run, but I seen some issues, and had to rebuild em, Ferrara valves, new valve seals, sportsman springs, and 4 angle valve job, plus some resurfacing and a mild port, WAY OVER the price of buying ready to run pro comp, patriot, or similar entry level aluminum heads. Now these are race heads, with GT40s you do all this and you are STILL not quite flowing like the aluminum head. With that said, if you can do your own head work or know someone who can do it GT40s are TOTALLY worth it and they are even better if they are ready to bolt on!! I hope that explains where I am coming from....

Talking cylinder heads.

Reply #12
Right now I have bbk shorty headers, a bbk h pipe, flowmaster 40s, and the mustang tailpipes so I have plenty of room to put intake modifications on. Some parts I have laying around that I am going to put on are some underdrive pulleys and a cold air intake. I think I'll be hitting atleast 200hp with all that on the car and the HO conversion should add atleast 30hp. I want the car to end up at the 350-400hp range when I'm finished can that be acheived with the 5.0?

Talking cylinder heads.

Reply #13
You will really want to upgrade the valve springs on the p heads I would suggest Alexsparts.com has great priced dropin spring kits and more for these heads especially if you go with ho camshaft.

Talking cylinder heads.

Reply #14
Lots of good info in this post...

If u r really looking for 350hp flywheel horsepower.... Hmmm

The gt40p can do it, but you will need a big cam, maf, injectors, big fuel pump,
Upgrade the springs like posted, because u will need to spin to 6000.
Now your stock aod/converter will fail or be very unhappy.

So, what to do...if u bolt on the gt40p and upgraded intake and TB.  The stock cam really is holding u back.
So catch 22...

So without fuel upgrades, computer upgrades...its going to be rough.
So how much money do/can u spend on this conversion?

Travis