Hi all, I have 2 sets of heads that I need some info on. The first set is from a 61-62 390 out of a TBird with a 4 barrel carb and intake. The casting number is C1AE-A.

The second set is from a 1968 F100 360 2 barrel carb and intake. These are emission heads and the casting number is C8AE-H.

I also have the 2 engine blocks from above and I need to know which would be better to use.

Thanks
Scott
1968 F100 SWB

 

C1AE has larger intake ports. What are the block casting numbers?

 

'68 block will have the 3 bolt engine mounts vs. the 2 bolt for the early motor.

Either set of heads needs hardened seats for unleaded gas, plus whatever else they might need owing to their advanced age.

What kind of engine are you looking at? A lo-po slogger or a giant killer?

 

Thanks guys, I forgot about the mounts so I guess I will be using the 68 block. I would like to build around 400hp without breaking the bank. The only thing I have so far other than the engine is an Edelbrock Performer RPM intake. The engine will be based off a 390 which will have to be bored but not sure how much yet.

Thanks
Scott
1968 F100

 

C8AE heads aren't "emissions heads". They're excellant heads, as for the ports being larger in the C1 heads, look inside the ports, some have a ski jump inside the port that makes the inside about the same size as the C8 heads. The C8's have smaller chambers for better quench and compression.

 

My heads have holes on top of the exhaust ports so wouldn't they be emission heads or are those holes for something else?

Thanks
Scott
1968 F100 SWB

 

Those are the Thermactor air injection ports. With them plugged there's nothing distracting from overall performance to call them "emissions heads" The C8AE-H came with and without them drilled/tapped, and with either the GT exhaust bolt pattern or the 8 bolt std FE exhaust bolt pattern. The smaller intake ports basically had the port floors filled, ala MR 427 style. As I said before check out the insides of the C1 heads, you may find that some of those port floors have a sharp rise just inside the port, making them no better than the C8 heads. I know the C4AE heads did.

 

Thanks for the info, I will check the C1's tonight. It still sounds like I would be better off with the C8's even if the C1's don't have the sharp rise just because they have the smaller chamber, am I correct?

Scott
1968 F100 SWB

 

I ran the C8's on the last 390 I built and I never saw the need to do otherwise. Course that motor only had 58,000 miles on it when I went thru it, the heads needed nothing more than new valve seals and fresh springs. It was in a 68 Merc Monterey, original engine. I overhauled it, changing two broken pistons out, new gaskets, rings, bearings, swapped in a Crane 272* Energizer cam, topped it off with a 428PI intake and 750 Holley and a set of FPA headers. Car ran 14.07@ 97 in the 1/4 with an open diff 3.70 rear afterwards (the Monterey is the same as a Galaxie) I'd run whichever heads need the least amount of work to put em in shape. If you're going to drive it a lot or tow with it, put hardened seats in the heads, if not I'd skip that expense and run a lead substitute to cushion the valves

 

Thanks for the info Baddad, I did check the heads tonight and you were correct on the C1's. There is a big difference between both heads and very noticeable rise on the C1's when you have them side by side. So I will be going with the C8's. Now my next question is do I go with the bigger valves or keep the stock size? I would like to be in the 400hp range and anything North of that will be fine! I am going to be running an Edelbrock Performer RPM with a 650 with Vac Secondaries, Heads and block will be milled flat and hope to come in around 10.1 compression and no more. Block has to be punched .030 over so that would be a 396. Cam is still up in the air as well as headers.

 

Do a cost comparison vs new Edelbrock heads before spending a dime on either of those old heads. Sometimes you'll end up spending more on the old heads when replacing valves, seats, guides, etc than you would by just buying new Ed heads.

 

If you intend to run headers in the truck, you may wish to see how they match up to the heads.