get a gauge tester with correct adapter for spark plug hole, let engine run to operating temp (promotes sealing and for accurate read), pull fuse to disable fuel pump, pull all plugs (so turns over easier) now thread the tester into the holes one at a time, order not important as long as you note reading for each, crank engine for a few seconds (easier with a helper) the needle on the guage will stop moving at max comp and remain there until you push the button releasing pressure, note highest reading ea. cylinder, all should be within 10-15 percent of each other. If any below 125 or so, rebuild time will be coming soon, any below about 100-110 are already close to misfire territory since a certain amount of pressure is required to make mixture explosive. Have fun
You will need to do either a cylinder leak down test or a compression test.
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?
A compression test will determine which cylinder(s) are at fault.
My truck runs about 140 psi, but was rebilt recently. 120psi is normal for a truck with normal wear.
Compression ratio on a 1974 Chevy 350 in a Nova was 8.5:1.
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.
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.
8.5 to 1 compression is factory stock.
the firing order for a small block Chevy 350 is 18436572
10.5-1