GT-40P setup questions

[capri2race]

As run of the mill it is to go with the GT-40P setup with the explorer intake, I have seen a lot of posts about how the valve springs suck. What brand and spec of spring should I look into buying? Also do I need to change the pushrods? What size TB should I run and should I step up to 24lbs injectors? I wasn't planning on swaping cams but I do have a used N61 Anderson cam that I thought of stabbing in but I don't believe there is sufficient valve clearance. INPUT PLEASE!!!

[cottonbear]

It's popular to use the trickflow spring kit and tfs stage 1 cam.
There are dozens of combos but that is a common one.

[93ksstang]

It's popular to use the trickflow spring kit and tfs stage 1 cam.
There are dozens of combos but that is a common one.

This is the set up I'm about to put in my car with the heads milled .010 and the block decked .020. Also another good set up is the same spring kit along with the Anderson n41 cam. Depending on what you want to use the car for will depend a lot on which route to go as far as cam wise.

[SVT Rob]

I've got crane dual springs in mine, and with the cam I have (XE274HR), I had to get slightly longer pushrods.

[SVT Rob]

Gixer7502006 used the Alex's spring kit, and he had to get longer pushrods when he put in the XE274HR cam in his setup, but with the stock cam, he had no issues with the stock pushrods.

[bwguardian]

As run of the mill it is to go with the GT-40P setup with the explorer intake, I have seen a lot of posts about how the valve springs suck. What brand and spec of spring should I look into buying? Also do I need to change the pushrods? What size TB should I run and should I step up to 24lbs injectors? I wasn't planning on swaping cams but I do have a used N61 Anderson cam that I thought of stabbing in but I don't believe there is sufficient valve clearance. INPUT PLEASE!!!

You will definately want to change the valve springs out to something that will match your cam specs. Be sure and also install the good blue valve guide seals. That Anderson N-61 cam is too big for those heads...not to mention you will more than likely need to fly cut the pistons, get longer push rods, etc. The other option you may consider is just leaving the stock cam in there and installing a set of 1.72 ratio roller rocker arms. However, if there are a few miles on the engine you may as well inspect the timing chain for wear and at that point a cam change is easy.

I have the GT40p heads on my car with a Ford Racing E-303 cam and a modified stock 4180c carb. If you are staying fuel injection the TFS-1 cam is probably the better cam for you...or something comparable. Just stay around .500" lift on a 112* LSA.

[Marz]

I have the gt40 heads on my 85 gt with a tfs1 cam and the stock modified 4180. It pulls well. But as said, with those heads the tfs1 cam would be perfect. Or, something with a similar lift. My gt has 9.5:1 compression with those heads

[edman1000]

I have an E-cam in my gt40p, rest of it is stock (pushrods, pistons, etc.). I did swap out the springs with a set of comp cams that required the top of the valve guide outer diameter (inside the springs) to be cut down a bit. They do make a spring that will clear it. Find that one (sorry I forgot who makes it). The Machine shop that cut down my guides screwed it up and now the seal dont stay on so it puffs a bit. Terrible screw up on something that didnt even need to be done!

[poetnprophet]

Not to hijack, but I've got an 86 GT EFI, and was hoping to do a similar setup: gt40p heads, intake, and TFS cam. However, I've read that the 86 in particular has flat top pistons and therefore won't allow higher lift cams.

Is that pretty much it? Or are there any cam/heads mods that I can do without swapping pistons?

[bwguardian]

Not to hijack, but I've got an 86 GT EFI, and was hoping to do a similar setup: gt40p heads, intake, and TFS cam. However, I've read that the 86 in particular has flat top pistons and therefore won't allow higher lift cams.

Is that pretty much it? Or are there any cam/heads mods that I can do without swapping pistons?

There is a tool you can utilize to fly cut the pistons with the dismantled heads while the engine is still in the car. I think the twisted wedge heads can also be utilized with a moderate cam.

[Johnny]

Not to hijack, but I've got an 86 GT EFI, and was hoping to do a similar setup: gt40p heads, intake, and TFS cam. However, I've read that the 86 in particular has flat top pistons and therefore won't allow higher lift cams.

Is that pretty much it? Or are there any cam/heads mods that I can do without swapping pistons?

I was told by a Ford Tech that you can go with 1.7 rockers on the 86 ( I have an 86 GT) making the lift go from stock .444 to .474 and this will give you more power and a little lope. You have to keep the lift under .500 (on the 86 5.0) or you'll need to fly cut the pistons. I plan on going with GT-40P heads this summer and going with the 1.7 rockers. It already has a GT-40 upper and lower. This setup with the other parts I've been hording,.the car should see 13's or high 12s I was told.

[85mcLaren]

That is ONLY true with the factory E6 heads. The valves are more recessed than the E7 heads. If you change heads to GT40 - you are screwed - unless you fly-cut....

Jason

[Johnny]

That is ONLY true with the factory E6 heads. The valves are more recessed than the E7 heads. If you change heads to GT40 - you are screwed - unless you fly-cut....

Jason

Thanks and yes I read what he said in the PM to me and you are correct! Only with the stock heads. Sorry about that.

[poetnprophet]

Well, that's a bummer. Thanks for the info and confirming that.

Would it even be worth porting my E6 heads? Has anyone done this, what kind of gains?

[bwguardian]

Well, that's a bummer. Thanks for the info and confirming that.

Would it even be worth porting my E6 heads? Has anyone done this, what kind of gains?

You could, I did it back in the day with the old D8 heads on my 82 given not alot of choices back then...lots and lots of time! It would be much much easier to get the tool, remove the heads, fly cut the pistons, install new GT40p heads.

[horsepowerjunkie]

I bought the through the head piston fly cutter from this company(http://www.lindytools.com/) It is a very nice tool & very simple to use!

[bmf347]

I bought the through the head piston fly cutter from this company(http://www.lindytools.com/) It is a very nice tool & very simple to use!

nice. I looked into getting that exact tool... glad to hear a review on it before my purchase

[LilRed86coupe]

Here's another cheap way to flycut your pistons:
http://sbftech.com/index.php/topic,15194.0.html

[94opalgt]

So, if I am reading this correctly. My GT40P head w/spring upgrade, B-cam and 1.6 RR's isn't going to work on my 86 motor without fly cutting the pistons?

[Digsj7]

You do not need to fly cut the pistons.

P heads, e-cam, exploder intake, crane dual springs, 1.7 RR, 19lb injectors, 255FP, 70mm TB, stock pushrods. That's how my 93 was set up and it made 265hp/300tq.

[94opalgt]

You do not need to fly cut the pistons.

P heads, e-cam, exploder intake, crane dual springs, 1.7 RR, 19lb injectors, 255FP, 70mm TB, stock pushrods. That's how my 93 was set up and it made 265hp/300tq.

Ya, but this is a motor out of an 86. 86's had flat top pistons, that's why I'm asking. Every other year had valve reliefs in the pistons, 86's do not.

[Wikd331]

anyone else have this issue with an 86 shortblock

[DrewM]

Why not buy the heads you want, clay them and see? If you need to cut valve reliefs then do so, it's not that difficult of a job, if you can change the heads on the car you can cut the reliefs, just a little intimidating the first time (but so was a lot of other jobs you do on the car).

[LSCR351]

anyone else have this issue with an 86 shortblock

I had a set of GT40's on an 86 shortblock with 1.6 rockers and stock 86 cam, worked fine. You can run E7's, GT40's, or GT40P's as long as you have 1.6 rockers, not shaved the heads, not decked the block, and have a stock cam.