My truck runs about 140 psi, but was rebilt recently.
120psi is normal for a truck with normal wear.
then youre running about 8.5:1 compression
around 80 ft.llbs. or higher is usually good.
head gaskets??? warped heads? did you have them milled?
Knowing the year would make a difference. A good STOCK 350 should have at least 150 PSI per cylinder. You CAN'T have any more then a 20 LB difference in any giving cylinder are you will have idling problems.
Compression ratio on a 1974 Chevy 350 in a Nova was 8.5:1.
Start by testing the compression. It should be consistent within a few PSI on each cylinder. Any cylinders that have little or no compression probably have a burned valve. If all cylinders are up, check the plugs, wiring and distributor.
The compression ratio of a 350 Chevy engine usually ranges from 8.0 and 9.0 to 1. This provides a good balance of fuel economy and power.
Usually at least 140-150 lbs.
8.5 to 1 compression is factory stock.
the firing order for a small block Chevy 350 is 18436572
The ratio is 9.5.1 in the 350 vortec. Doing a compression test you should not have any below 100 psi and all should be similar to each other.
Remove all the spark plugs and turn the engine over by hand. Place your thumb over the #1 plug hole and you will feel the pressure on the compression stroke. A compression gage will also tell you when you are on the compression stroke.