[Keifer]

This ones got me stumped, so here's some background.
350 sbc just starting to restore the truck. I put on some valve covers one night and I unknowingly pinched the vacuum advance to the distributor. Had a misfire underload and thats how I found the line. No big deal replaced the line. Few days later and I go to start and it has multi cylinder misfire. So I try to figure it out:
Got fuel, 6psi got spark on all 8 cylinders. From what I can tell I have 3 contributing cylinders (#2 #6 #8) from feeling heat on the headers, the rest of the cylinders are stone cold. Pulled spark plugs they are wet from gas but they don't look bad at all. I don't know how timing can be off since I have 3 cylinders that run good, and compression is solid. I haven't touched the intake manifold so I doubt there's a leak however at this point thats all I can think of since the entire drivers side bank is dead.
Ideas?

 

[chasracer]

You checked spark at spark-plug end of cables? Put a new set of plugs in and see how it goes. You might have a timing gear going or some chain stretch involved but with one solid bank dead it's funny stuff. Have you checked the firing order to make sure of it? And what are the compression numbers?

 

[2old2fast]

Is this a high mile engine.? Might want to check the timing chain

 

[BogiesAnnex1]

What is the intake, generally if a dual plane, these feed 4 cylinders with 2 on each side front one plane so all wet cylinders on one side is rare. Even a single plane doesn’t tend to do that unless one side of the carb is really over rich. A single plane with a plenum divider can do this easily if one side of the carb is over feeding fuel.

Modern peanut spark plugs once fuel wetted are shot. The chance of successful reuse is pretty slim.

This could be one side of the engine not firing the plugs or not running if the plugs do fire. The likely hood of this being a distributor problem is not high. Miss-adjustment in the valve train or wear of cam, lifter or other pieces in that link are high.

If there is a 6AL box it could be interfering with ground paths but that tends to be more random than just one cylinder bank.

Too wide a spark gap on one side, I like to keep ‘em tight at .030 to .035. Given these usually come 4 to a box, it could be one box got gapped to wide.

Deeper can be serious error in engine assembly from wrong pistons on one side lowering compression height thus compression, or a thick or a missing head gasket as examples.

Boie