[TorinoStyle2]

Maybe the timing chain has jumped a tooth.
Could be a burnt intake valve thats not sealing off the combustion chamber.
Could be a broken valve spring or a wiped out cam lobe and lifter.

 

[TorinoStyle2]

Maybe the timing chain has jumped a tooth.
Could be a burnt intake valve thats not sealing off the combustion chamber.
Could be a broken valve spring or a wiped out cam lobe and lifter.

 

[eliteman76]

Um, you SURE you have the timing correct?
I have a 1970 351c, and as I and a freind found out, we somehow got the f{bomb} distributor backwards 180 degrees. I had the heads redone, we were putting the engine back together, couldn't get it to fire. It about took my buddies head off with the first backfire.
I had set #1 at TDC, and he wasn't paying attention to the correct
mark, used an old one I put there.
Once we found that out, it fired.
Otherwise, I'd say maybe the chain. Does it have the original Nylon tooth sprockets??

 

[FEandGoingBroke]

A flat cam lobe will do that.....