fattest cam in a 340?

Like mentioned a bunch, put at top dead center, mark balancer and see what happens when you time it. Get a piston stop, degree wheel, timing tape and do that properly, don't eyeball it. Go to YouTube and type in "using a piston stop to find TDC", lots of results come up to show you how. Definitely possible the balancer could have slipped, this will confirm that.

I had a 360 years ago that I put a comp cam in that had .525" lift, I think it was a 308H, maybe. I had stock everything for heads and valve train, I would wind it out to over 6500rpm often, not sure how it pulled to that with stock springs. Only other major changes was 4000 converter and 4.56 gears. Was a fun light to light car 20 yrs ago. Just some reference for you on size I've seen work with nothing done to guides etc.

Cheers