400 sbc stock. comp with 64 cc heads

Hello . i am looking .at putting a set of bowtie phase 2 heads on a 1975 400 sbc .they r 64 cc heads .wondering what my comp.ratio would be .also have a set of 65 327 heads .with 202 1.6 valves installed .they r 60 cc .dont no wich to go with . it will be used for drag racing .. the 400 still got lots of life in it figured why not run it till she goes .. thanks for your time ..


Register now (free) or login to remove ads

Somewhere around 7.1:1. Or 14:1. Or 9.7:1. Or...

Is it further to Cleveland, or by bus?

Ok boy that helps alot ..9.7 maybe close i dont no that is why i am asking ..

LOL

Please give the forum some details of your engine and there will be some hope of guessing at your CR.

Well i would think there is enough info there for someone who knows Chevy to figure it out ..all i am asking is for comp ration from a stock 400 sbc 1975 with 64 cc chambers .which would of had 76 cc heads stock .. or the 60 cc heads .and which would be best .for drag application . i would think the flow rates of the phase 2 would be better for upper rpm where the motor will b in most of the time .or if the other 4 cc would make that up for the extra comp .

If your stock 400 was 8.6:1 with 76cc heads then with a 64cc head the cr will be 9.65:1 and 10:1 with a 60cc head on it. Assuming the same head gasket volume is used.