Hey guys, I got a conundrum inside a delimma wrapped in an enigma.
I'm puttin' my crank in my production 350 ( .030 over ) and I look in my
Chilton's manual for the torque spec and it says 85 ft/lbs.Everybody tells
me it should be 65ft/lbs. So, I call the company that made the crank and
they say to go with the manufacturers spec ( according to Chilton's - 85
ft/lbs ). Then the guy talks to someone else at the shop and says that it
should be 65 ft/lbs. What gives ??? Also, should I replace the main bearings
after torquing them to 85 ?
Any help is greatly appreciated .


So You're Jack Wilson.

Alan Ladd ( Shane ) - 1953

 

Chilton's is not the manufacturer. At least, not of the crank, the block, or the bolts. All they manufacture is books.

The spec is 60-65 ft-lbs., with lube on the threads.

No you don't need to replace anything except maybe the bolts.

 

Just looked it up in my 89 GM factory shop manual for f-bodies. For a 2 bolt main block, it says 77 ft. lbs. Oil pump mounting bolt calls for 65 ft. lbs. IIRC, on a 4 bolt main block, you're supposed to torque the longer, inner bolts to 75 ft. lbs. and the shorter, outer ones to 65 ft. lbs. Overtigtening the bolts won't hurt the bearings any, but like Sofa said, you may want to consider new bolts. It's remotely possible that they could've been weakened by being stretched too far. It's your call on that one. They'll probably be fine, but if you're picky like me...

 

Replace the bolts. 50$ for arp bolts is alot better than replacing the botom end.