Engine back fires and sputters./.."

OOPS, sorry, I missed the backfiring part. I'd say it's an intake valve
problem, But I doubt if you need to pull the whole block. jsut the
head...BUT, I'd pull them both and have the job done right. You might
be doing some preventive maintianence by haveing the other head
inspected as well.

Tim

When I pulled mine (1986 350) heads for a stuck valve. Both Heads had
cracks in the Exhaust Seats, clar thru to the water jacket. This is
apparently not uncommon for GM small block engines running with a high
load.