Hello I usually hang out on the 48-56 F-1 board, this is my first post on this forum. My question is about aluminum heads, I see the higher end heads Eddelbrock in partiular, use thread inserts in the exaust port threads and rocker stud threads, and the lower quality heads procomp in particular do not. Has anyone had expeierence good or bad with stripping or pulling out the threads that are just tapped into the aluminum vs the threads with inserts? My motor is a 68 302 with the Eddelbrock performer package, 600carb, intake, FT cam, lifters, timeing chain, stiffer push rods and springs. It also has tight tuck headers with dual 2 1/2" pipes and twin glass packs. It was rebuilt by PO, and as of now I dont know about the lower end. The Motor is srpriseingly spunky from 0 to about 3k to 4K RPM, and with a straight axel, stock steering, and suspention thats what I want low end torque for the ocasional lite to lite. Im on a tight budget and would like to complete the package, but would rather save up for the higher end heads, or go with iron GT40s, than buy something that could be junk. Ive read all I could find by researching, but would sure appreceiate your input. Thank you in advance "JIMMY" PS I havent pulled my heads, but if they turn out to be C8OE-Fs with the 53.5 combustion chambers and there 10 to 1 compression, should I just leave it as is?

 

Well, I have no experiende with Aluminum Heads, but if can believe the ads the "Ford Racing Turbo Swirl Aluminum Heads" are the Aluminum-Version of the GT-40 Heads.

Ford Racing 302/351W Turbo Swirl Aluminum Cylinder Heads M-6049-X306 - SummitRacing.com

 

Thanks for answering, Yes those would be nice, they advertise 65 hp out of the box, I dont have much motor expeierence , I did the cam and stuff to this motor and Ive rebuilt a six cyl,and a c4 tranny, but Im just one level over an oil checker LOL. I do ramble but my real question is do studs tend to pull out of bare aluminum?

 

Studs should be okay in aluminum, it's bolts that will cause trouble. I've had a few aluminum headed cars (Toyotas, Escort, etc.) and never had trouble other than the rocker shaft bolt holes stripped on one Toyota, probably from previous abuse. But those were bolts, not studs.

 

Thanks for your input Beanscoot, its appreceiated very much.

 

Thread inserts are a plus in aluminum heads. But at the same time, you must use a thread lubricant (copper or aluminum based) to insure that the steel bolt (or stud) does not fuse itself to the aluminum head when left in service for long periods of time. There is a quick way to check to see if you have the 302 4V heads, that is cast into the rocker area on those heads. If it's not there, they're not the small chambered 302 heads. The small chambered 302 heads are basically the older C6OE 289 heads remade for the 1968 302 4 bbl motors. If you're going shopping for 302 heads, look only at those with 58 cc chambers. The difference in the comp ratio between using a 58cc vs a 64cc head is somewhere between a half and a full point in the ratio. You can easily mill 58 cc heads down to 53 to get a boost in compression. Milling 64cc heads by .060 only gets you to 57cc's, anything past .040 gets you into intake bolt alignment problems, and sometimes into having to mill the intake too, to get it to fit afterwards.

 

There are big differences between the iron and aluminum GT40 heads. The GT40Y heads were the closest to the GT40 iron heads(not the GT40P) in power production, the X heads were a big step up above those.

 

If this is all you want out of it, then forget changing the heads. Putting better heads on will be a no win situation, that intake and carb will only serve to put a restriction over what the heads offer. And without knowing what the bottom end is comprised of (cam, pistons) you could be going backwards in choosing the wrong heads for what they're going to be bolted to. Better heads will generally move the power band upwards, but doing so with that intake will only serve to cancel out any meaningful gains they offer.

 

The threaded inserts can save the head. instead of destroying the head, you just have to replace the inserts. I have edelbrock performer 170s on my 88 mustang. there was a HUGE power gain over the stock E7 heads. but if you want best performance out of the box, hands down the trickflow twisted wedge heads are the best. with AFRs new head in a pretty close second.

 

Thank you for the education, and for explaining what the add's do not. There is nothing like expeierence, and I sincerely thank you ALL for sharing yours with me. Happy Holidays.