Heads Compatability Question

[HotRod929]

I have a 1970 Chevy C20 with a 350. My friend has a 1970 400 small block and was gonna sell me his camel hump heads for $100. I know these are really good heads but was wondering wether or not these would fit on my 350. If so I will be deffinatly buying them. Please let me know. Also how will these heads improve performance and will they rase the compression or not. Will I have to make any other changes or are these pritty much bolt ons. Thanks

HotRod

[67dragtruck]

All sbc production heads will bolt to a 400 or a 350 so that part is not a problem. As to the compression part it depends on the cc of your combustion chambers now. The double humps will have 64 cc chambers if they have never been surfaced. If you have a 350 with flat top pistons you should net a 10.25:1 ratio with a .040 head gasket. Will work fine with pump gas. The only other difference in a 400 head are steam holes that are in the factory 400 heads that may or may not have been drilled into the double humps. Shouldn't cause a problem either way. If the chambers look stock and haven't been opened up for the 400 bore then they are a bargain.

Tom

[lukecp]

As 67 said, they will bolt right on without problems. They will bump your comrpession up quite a bit. If you have flattop pistons you will have to run 91 octane fuel, or 89 with a vaccum advance kit and re-curve of the distributor (you could also run 8* of base timing too, but the vaccum advance curve kit works better).

I have a pair of 64cc camel humps on my truck and i can run 89 octane no problem, but it does run a little better on 91 and REALLY good on 93

Anyway, a bare pair of crack-free camel humps is worth $100 in rebuilding condition, so it sounds like a good deal. Make sure they have hardened exhaust seats though so they will be compatiable with unleaded fuel. They will be even better if they have 2.02/1.60 valves (although they proably don't).

Another think to look into is if they have accessory holes or now. It they don't you will either have to drill the accessory holes or get a kit to mount your alternator. The holes are in the end of the head...look above where the double hump markings all and see if they are there.

Anyway, $100 is a good deal for a runable pair of double humps, and they should help out in power over a pair of somoggert heads.

[smitty62]

To make sure they are what you want, get the casting numbers and check them out at www.mortec.com. Or list the numbers under the engine portion of this forum--someone will tell you if they're any good!!

[JDL]

If you want to use the for very much street use you need to put hard valve seat.