I need some help on this. just bought the 455 olds motor it has been somewhat taken apart down to a short block. I need to know if the g heads are worth puting the money into? I don't know what the cc are and if i can use them and flat top pistons to get around 9.5 to 1 in comp. this will be my first olds motor build so i will need some pointers on the in and outs of building an olds. the engine is going in a 67 vista cruise with an auto tranny would like to build as much horsepower in it as possible and kept a stock converter. i'm looking at a comp cam but don't know which one would be the best fit. will punch in out 30 also.
Thank you in advance Charlie

 

Yes the g heads are cool you will need to use dish pistons as flat tops would increase the compression a lot.

 

G heads are from the 1971 model year. They have hardened valve seats and about 80 cc chambers (as to all big block Olds heads). They are a good starting point. The factory high compression pistons had about a 6 cc dish. Today's 0.040" compressed thickness head gaskets will drop compression about half a point or so from advertised CR for a given set of pistons. The advertised CR usually assumes a thin sheet metal head gasket.

 

Look closer - they should be GA heads. There will be a smaller capital "A" to the right of the G. If they are just G, then you have 1971 heads.
Terry

 

Thank you all for the info. Is their some place i can get a stroker kit for this motor?

 

www.btrperformance.com/

 

Welcome to CO, I see you already got some good help from our members here, great!

 

I took a closer look at the heads they are not g heads they are GA heads
so are they as good as the g heads or do I need go go to after market heads?
Thank you

 

The Ga are good heads that used the large valves no need to go after market.

 

Thank you 72cutlass455 that will save some cost that can be put to good use else were in this restore.