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Old January 23rd, 2017, 12:41 AM
1972RedNeck 1972RedNeck is offline
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Join Date: Dec 2016
Location: Townsend, MT
Truck: 1965 GMC 5000 6X6
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Default 478M Loosening Rod Bolts

So I have a line on the front half of a '74 GMC 8500 with a 478M, five speed, and four speed OD brownie. The engine has had multiple fresh rebuilds. Apparently, after the first rebuild, one of the rod caps came loose. They pulled the pan, put a new bearing in it, and torqued it back to spec. It came loose again, and another time.

It was torn completely down and all new rods and pistons were put in. And it shortly thereafter developed a rod knock and was parked.

What do you all think could be the problem with it? The price is right, but I don't really need something that I can't fix either...
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