Changing heads, need help.....

[dbbullet]

Hey guys I'm planning on swaping a pair gt40p heads on my 94 ford mustang gt. Here are the specs on the heads:

Ford GT40P
60cc Combustion Chamber
Pedastall Type Rockers Used
Positive Oil Control Seals
5 Angle Valve Job
Stainless 1 Piece Swirl-Polished Under-Cut Stems 1.940” Intake Valves
Stainless 1 Piece Swirl-Polished Under-Cut Stems 1.540” Exhaust Valves
AWSF-32C Spark Plug
Springs Good to .550” Lift, (Hyd. Roller) *check cam manufactures specs for compatibility*
(129 psi @ 1.800” / 280 psi @ 1.300”)
I'm also planning on a Ford Racing E303 cam 2500-5500 rpm range.
Could I use the stock pushrods and 1.6 or 1.7 roller rockers?

[351wStang]

Your question has already been answered. I don't know if you didn't like the answer you got, maybe it wasn't what you where looking for...? But the correct answer stays the same. We cant tell you if your stock length pushrods will work. But if you don't listen to anything else I have to same listen to this. If you do determine that stock length is the correct length pushrod then at least buy new stock length pushrods. They are thin and your stock pushrods have been used for quite a while I'm sure. Not to mention if you do upgrade your rocker arms then you will want new pushrods because the stock pushrods are "trained" to the wear pattern on the stock rocker arm that they came off of.

Your E303 cam has a base lobe lift of .311, with a 1.6rr the lift is .498, but with a 1.7rr the lift is .529. I know that my F303 cam (.512 lift with a 1.6rr) will not work with a stock 5.0 short block and 2.02 valve heads. The intake valves hit the pistons. I would venture to guess that your E303 cam (.529 with a 1.7rr) will not work on a stock 5.0 short block unless you run a stock ration rocker arm (1.6).

[eillob]

There are plenty of guys here in the local club running E cams with 1.6 and 1.7 roller rockers around here. So my answer is go for it. You shouldn't have a problem with what I see in your combo. If you are dealing with the stock shortblock, pistons and the heads are new and haven't been milled to death there shouldn't be any clearance issues with either RR. So long as you are using 1.94 intake valves. The 94-95 stang has factory notched pistons so 1.94 intake valves are about as big as you can go. Just for the record you cannot compare a 1.94 intake valve to a 2.02 intake valve when it comes to cleance issues. The 2.02 intake valve is huge in comparison and requires fly cut pistons unless your running trickflow heads. This is one of the reasons the trickflow heads are so popular. It is one of the few heads that you can buy with 2.02 intake valves and in most cases not have to worry about fly cut pistons. However when in doubt check.

With regards to pushrods, yes you can use your old ones. I have done it a few times and never had a problem, just do yourself a favor and check them for length and wear. If you can afford to buy new ones then by all means go for it. But you can get away with using the stock ones for your particular combo. When you start getting into bigger cams with double and triple springs then you better go spend the money and get some good pushrods.

[351wStang]

I've never dealt with GT40 heads, but I remember talking to a guy running them on a stock '89 5.0 and needed a non-stock pushrod, maybe he was just confused or something. If you can get away with stock length then go for it. But if nothing else go thru the process (it doesn't take long) of checking for proper pushrod length. If the pushrods are the wrong length then you're gonna hate buying new valves because yours are mushroomed.

[dbbullet]

Thanks for answering, one more question though, after a lot of research I finally decided to go with trickflow twisted wedge heads since they don't require flycut pistons for use with cams up to the specifications listed and wanted to go with bigger valves 2.02/1.60. I know it probably sounds stupid but I really don't know, what does O-ringed and non O-ringed means?

[351wStang]

O-ring'd heads have a metal "O-ring" that seals the combustion chamber to the cylinder. This is for heavily boosted or large nitrous applications. The block must have a receiver groove cut in it to use these heads. Once you O-ring a block, theres no going back. Non O-ring'd heads are surfaced just like your stock heads.

[dbbullet]

Thanks 351wstang, your help is apreciated!!!

[351wStang]

No problem. How about some progress pictures.

[dbbullet]

Yes, as soon as I get a chance.