Kill me now, please.

crackedback said
Could the tensioner be adding a bunch of drag? I never run those things, just a thought.

I would have to say, no
my 408 has a tensioner on it, and I can turn it by hand with a 1/2 ratchet on the crankbolt

my money would be on a cap put back on wrong and possible bearing damage to the bearing under that one cap