I am in the process of rebuilding a 1991 350 TBI out of a K1500 that has been disassembled for a couple years now. It had spun multiple bearings and was torn apart. I have installed a new Summit Racing crankshaft (part number: SUM-180366) that is said to fit a 5.7L from 1986 to 2002. When I went to thread the original harmonic balancer bolt into the crank it was obvious the thread pitch was different, so I bought a new Jegs bolt and it is vastly dissimilar to the original but threads into the crankshaft fine. I am confused why there would be different bolts for the same year truck. Also, I am realizing that the harmonic balancer is much too long for the crankshaft and if installed would only be about 2/3 of the way onto the crank. My first thought was the double chain timing kit I have installed is wider than OE, but I cant find any information supporting that theory. I might be able to find the original crankshaft. Just seems like this new one is somehow too short. Any advice appreciated.

 

I found the original crank with the actual bolt in it, not sure where this one came from. The amount of crank leftover for the balancer is identical on the original crank. Oops... how do I delete a thread