There were two 350 engines offered in 68. The standard engine was about 8.5 to 1 and the HO version which was advertised at 10.5 to 1.
I'm assuming you mean static compression ratio. There were two 350 (5.7) engines offered by Pontiac. The standard engine was around 8.5 to 1. The HO version was factory rated at 10.5 to 1.
8.5 to 1 compression is factory stock.
About 8.5 to 1
No.
then youre running about 8.5:1 compression
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.
43.75 cubic inches.
the piston in cylinder #1 at the top on the compression stroke
A compression test will determine which cylinder(s) are at fault.
around 80 ft.llbs. or higher is usually good.
8.5:1 stock
Usually at least 140-150 lbs.