140-150 lbs.
do it with engine warm for better sealing, pull all the plugs so it is easier on the starter and disable fuel for the test
compression test or leak-down test.
it depends if you have a 305 or 305ho , 305 8:1 compression cupped cylinders 305ho has 9:1 compression with valve cut pistons
You may have compression on any cylinder where the valves happen to be closed, but you will not have compression on all cylinders. 1991 Sable does not have a 305 engine.
when my 305 is running it has about 60 psi in all the cyliner
8.3:1 is stock
Higher compression ration which can increase hp. I installed 49cc heads on my 305 instead of the 64cc and got a higher compression ration and a fair amount of hp gain.
Yes they will, but 305 heads have a smaller combustion chamber so it may raise your compression ratio.
Yes, but it increases compression a full point.
No. It lowers the compression ratio and reduces power output.
The average is 289.