Help With GT40 heads

[TorchRed_4.0]

I have a set of GT40 heads and recently purchased an E303 cam to go with them.

My question is will those pair together and if so what all do I need to make them work together such as pushrods, springs, etc.

 

[Mustang5L5]

It’s a combo that’s been done plenty of times.

I’d recommend a spring kit from Alex parts

FORD, SMALL BLOCK 302 HO w/ E7, GT40P & GT40 - Alex's Parts Sales

www.alexsparts.com

You’ll need to measure the pushrod lenght, and I would stick with the factory 1.6 rockers. You can spend the cash on some aftermarket 1.6s but I don’t think your $$$ spent will be worth it here .

 

[limp]

 

[TorchRed_4.0]

It’s a combo that’s been done plenty of times.

I’d recommend a spring kit from Alex parts

FORD, SMALL BLOCK 302 HO w/ E7, GT40P & GT40 - Alex's Parts Sales

www.alexsparts.com

You’ll need to measure the pushrod lenght, and I would stick with the factory 1.6 rockers. You can spend the cash on some aftermarket 1.6s but I don’t think your $$$ spent will be worth it here .

I take it the stock GT40 springs can’t handle that e303?

 

[7991LXnSHO]

I take it the stock GT40 springs can’t handle that e303?

I do not know about all GT40 heads, but the gt40p heads’s stock springs are limited with the stock E7 5.0 cam.

 

[Black1987]

I take it the stock GT40 springs can’t handle that e303?

Most of the time no unless they have been upgraded. You can always check coil bind, but Alex kit is cheap assurance you won’t float and smack a valve

 

[Mustang5L5]

Except that they are out of stock and have been for a while.

You may have to call and ask them to scrouge a kit up for you.

Trick flow makes a kit as well but tbh I like the Alex parts kit better for some reason

 

[TorchRed_4.0]

Except that they are out of stock and have been for a while.

You may have to call and ask them to scrouge a kit up for you.

Trick flow makes a kit as well but tbh I like the Alex parts kit better for some reason

Could you give me a link to some springs? I don’t want to buy the wrong ones, I just need some springs that go on the GT40 explorer heads that will work with the e303 cam.

 

[Dan02gt]

Buddy of mine ran a E cam on stock E7s for years with stock springs. Engine ran great. No float at all. Now we did try a set of 1.7RRs on it for the heck of it and that was a no go! Floated bad over 4500 RPMs.

 

[TorchRed_4.0]

Buddy of mine ran a E cam on stock E7s for years with stock springs. Engine ran great. No float at all. Now we did try a set of 1.7RRs on it for the heck of it and that was a no go! Floated bad over 4500 RPMs.

I’m not trying to be cheap, but if I can save $200 that would be awesome. Do you think I can get away with stock springs and the E303 or should I just go ahead and upgrade springs?

 

[7991LXnSHO]

Get matching springs so you do not have to wait for float or for it to drop a valve.

 

[General karthief]

Say you save $200 by not replacing the springs, you're out cruising and hit the 'happy peddle' and miss a shift, valve float for a millisecond and kicks a retainer out or breaks a valve stem, BAMN!! You just threw that $200 out the window along with several more hunnert dalla bills.
Or it could run along just fine schlepping over to the cars and coffee on Saturdays.
I like a 'awh ' cushion. Do the valve springs.
DISCLAIMER: this is an opinion and not based on any real mechanical experience.

 

[Mustang5L5]

The source of your GT40 heads should be taken into consideration. Are they early '96 heads off an explorer? Then you want to change the springs. E7 springs would be an upgrade over the stock truck springs. Are they off a 93-95 Cobra? They might be fine. No idea where they came from? Change them for piece of mind.

 

[Dan02gt]

I’m not trying to be cheap, but if I can save $200 that would be awesome. Do you think I can get away with stock springs and the E303 or should I just go ahead and upgrade springs?

If you can find springs for $200 or less I would do it. Better to be safe.

 

[Rcdgl]

Absolutely need to upgrade the valve springs. I used Comp Cams stuff on both sets. The set on my 82 worked perfectly with a stock (flat tappet) cam and stock pushrods with the orig bolt down rockers. Good to 6200 anytime. Need to check carefully, I needed different height retainers for intake and exhaust. Comp has them.