Fishhawk

I'm in the process of adding a new Edelbrock manifold, heads, and cam to my 85 GT. Since my motor was the first year for the roller cam and last year for the Holley carb I am running into some confusing numbers regarding a cam. I have narrowed my choices to the Edelbrock 3722 roller cam or the E-303 Ford Racing cam. They both have the same duration and lift but say that they will only work with 86 and up EFI engines that have Mass Air Induction. My question is, how does the cam know the difference from a Mass Air EFI to a Holley carb? Crain and Comp Cams say not to worry about it then give me the hard sell trying to get me to buy direct from them. Any suggestions or advice would be greatly appreciated.

vfast

well first the 85 has I think only 2 valve relives on the pistons which almost any biger cam will not work due to this...so go to a longer rocker arm is about all you can do.....

86HOGT

Saem thing with 86's also. In order to get different Rockers, or high lift cam, you have to change the pistons. Good for stock, not modding.

Fishhawk

But if I use the Edelbrock heads with 1.90" valves instead of the 2.02" I shouldn't have to notch the pistons and the stock one's will be fine.

vfast

no, you will have to notch the pistions as the relief isn't big enough for 1.90 valve..look at thier web site

Fishhawk

Here's what the website says:
They accept 1982-95 5.0L V8 pedestal mount rocker arms and valvetrains. 1.90" intake valves are for use with stock pistons and 2.02" intake valves are for aftermarket pistons notched for valve clearance. These heads will not accept rail rockers. Ford 5.0L engines require Edelbrock Head Bolt Bushings #9680 and either Edelbrock Head Bolt Kit #8552 (7/16") or stock head bolts. See chart for more specs. Note: 1986 5.0L must have pistons notched for clearance.

I know it says the 86 5.0 must be notched, and that bothered me when I was talking to the Edelbrock tech, but he insisted that that was for the 2.02 head and my 85 won't have a problem. Also he mentioned that I can't use the 1.7 rocker because of clearance and would have to stick with the 1.6. The next day I called again and got a different tech on the phone and he also said that they are refering to the 2.02 heads, and my 85 would work with the 1.90.

Fishhawk

I just paged through the Ford Racing catalog and the GT-40 Y-303 head says the same thing as the Edelbrock heads about the 86, but just the 86. Now I'm really confused. Going to have to call again tomorrow to Ford and Edelbrock (For the third time) and get these guys to look at their own website and pin them down once and for all. (If you can't trust you're Ford tech, who can you trust?)

Fishhawk

I finally have this figured out. The 86 GT was the only engine to have flat top pistons with a completly different set of heads. The 85 has the valve relief. As long as I don't go beyond .500 lift and stay with 1.6 roller rockers I shouldn't have a problem.