I bought 440 source 505 stroker kit, had it balanced by them also, had it checked over by a machine shop with no problems found, I'm sure if there was they would have jumped right on it as they didn't cut me any slack on the machine work on the block. Been racing it for about 4 years, hundreds of runs with no problems, I'd by another by the way it runs low 10's.

it's ok to butt heads, just don't do it with a butthead