Anyone ever use the summit stock replacement cylinder heads non Vortec looking for a cast iron head for my 400 small block nothing fancy motors going in a daily driver comp 268 camshaft
-12.5cc volumeWhile I have heard mostly good about their heads, I would be concerned about this particular choice because of the 72cc chambers. Unless you are running dome or at least flat top pistons, your compression could be pretty low with the large chambers (think 7:1 to 8:1 with factory dish pistons).
I realize that power isn't a primary concern, but if the money is going to be spent anyways, 64cc or maybe even 57cc heads are going to up your compression and make the motor more efficient for the same money spent.
Also whatever you buy, don't forget to drill the steam holes.
You would have to contact Summit and ask what is appropriate for that head casting. Once you get away from a factory GM casting, you just don't know where the cooling channels are.So when I drill the holes in the new heads are the ones towards the intake face on an angle or the ones on the exhaust face on an angle
My Brodix heads came with holes drilled straight in unlike the factory ones
I plan on using my Bridgeport mill so I have a better chance of the angle being spot onI have a 406 in my 71 and I used World products Sportsman II 220's.I drilled them at home with a drill press using the factory angles but I agree the steam holes have to meet the coolant passages correctly.I will try to find the angles for you and post them, but when you look at the 400 head gaskets against the head you can see how the steam holes go.IIRC you drill the exhaust side of the head straight down this matches a hole on the blocks deck and the hole on the intake side is drilled on an angle but this hole also lines up with a hole in the deck.
OK I found some info that tells how to drill steam holes :
Drilling steam holes in smallblock Chevy heads
www.crankshaftcoalition.com
There is more information about drilling steam holes on the Team Chevelle web site.Do a search on the forums on Team Chevelle.......www.chevelles.com ...... you will find a lot of Chevy information on there and its free to sign up, that way you don't get bombarded with commercials
The other thing about drilling those heads is to get in touch with the manufacturer of those heads and let them know they're going on a 400 SBC.You're gonna love the low end torque that motor puts out but if it's going in a street motor it will run HOT without the steam holes.
We are getting off topic here I wanna know about the cylinder heads not drilling the steam holes that’s 80s newsYou would have to contact Summit and ask what is appropriate for that head casting. Once you get away from a factory GM casting, you just don't know where the cooling channels are.
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