Bill, et al...
I think this might be a stretch but... What about the head gasket? Could the shop have installed the wrong one? OK anyone... I've never compared a 235 to a 230 / 250, are they close enough that one might be able to put a 230 on a 235? (Where the bores, pushrods, bolts line-up, but not the water jackets. Just thinkin' out loud, er... "on-line" here!)
