kayosnes

Can anyone tell me how large my stock 73BB heads are.
My compression rate now is 8:25.1
And i was wondering what compression i would have if i put in 110 or 100cc aftermarket heads.
(Are looking at edelbrock RPM)

BB wowbagger

I belive that you should have #781 heads. The should be around 118cc.

kayosnes

You now what compression i would get, if i went wit 110heads
and what i would get with 100 heads???

Thanks for info

Jughead

You can go HERE and figure it out.

I think Procrastination Racing is a member here.

If you don't know head gasket thickness & amount in hole you could use 0.049

Problem with this type of calculator is that you don't know what value to use for the piston volume. I guess you could use zero as an example and just change cylinder volume.

cyl dia = 4.251
stroke = 4
chamber = 118
piston dome = 0
gasket thickness = 0.049

Compression = 8.18.

changing to 110 cc heads = 8.66
100cc heads = 9.348

73 LS-4

The stock 73 heads are the 049 castings, arguably the best large oval port head as cast for flow numbers. But they are handicapped in two ways, one the cc's on the cumbustion chambers are 119, and they run the smaller valves 2.06/1.72. If you can get the compression up a little bit and install some larger valves and due a bit of pocket porting they are great street heads.


Pat Kunz

kayosnes

thanks for good info. That answer my question