How can I tell if a cylinder head supports the air injection system? Can a head be drilled to support it? The reason I ask is because I noticed those edelbrock heads are 50 state legal!!! They even have bigger valves so I guess that really doesnt make a difference. I did however notice that they had provisions for the air injection system. I am beginning to like the idea of swapping heads from an earlier model 302.
David, the 68 heads that I have are not drilled for the air injection system. What year maverick do you have? Did any of the mavericks have air injection? I know that some mavs had EGR and gas tank purge canisters but I don't recall if any had the air injection. I'm currently running the 91 heads on my car with the EFI but the air injection is blocked off.
Well mine is a '77 and it does have the air injection. Is it even needed for emissions then? Do the 68 heads atleast have the egr system?
David, here are some pictures. Note, on the one with the combustion chamber you can see the C8OE casting date. The other image is a pic of the screw in studs, guide plates and dual valve springs.
EFIMAV, I found a set of heads at a swap last year, so I won't need yours. They were a 1970 302 casting, the 60cc chamber, screw in studs, roller tip rockers, and a 5000 mile old valve job for $75.00. I ported the air humps out of 'em, now all I need is hardened seats in the exhaust and I am ready to go. The nice thing about the aftermarket heads, they sure made a lot of the old cast heads really cheap sometimes.
Since I started porting heads professionally in 1991, I have ported well over 100 sets of stock Ford heads, and at least that many Ford aftermarket heads, all with the aid of a SuperFlow SF-600 fow bench. Some things of interest that I have found: 1. A properly ported set of stock heads can run as good or better than a set of stock aftermarket heads, and will run rings around the GT-40 variety. And they are much more user/installer friendly. 2. EVERY oem SBF head that I have ever worked on has had induction hardened exhaust seats, even a 1963 221. 3. When I install larger exhaust valves(1.6"), I NEVER put in hardened seats, and have not seen ANY problems whatsoever with seat recession. Some of my earliest heads have passed thru multiple owners, so i see them back on a regular basis. IMHO, the "Hardened Seat" myth is one perpetrated and passed on by the monthly rags. Valve seat recession is a very real problem on some heads(FE Fords, 440 Mopars), but not on SBF's or SBC's. 4. You can run a TRUE compression ratio of 10.5 : 1 with iron heads, over 11:1 with aluminum, with typical mild street cams on Premium unleaded. True C.R. is determined by careful measurement, it is NOT what is printed on the piston box. 5. My porting efforts before I bought the SF-600, as time consuming and beautiful as they were, stank. Find a good professional, pay him what he deserves, and you will be rewarded with an engine with a completely different personality. One that you can use a small(or stock) cam in that will run so well that it will scare you!
