[bigblockv6]

David, what you need for a replacement is the ring gear that was used on GM light duty trucks through out the 80's with the 6.2 GM Diesel. When I had to get a custom built flywheel for my 478M that was going in my K-2500 Tilton Engineering built me a flywheel to the same dimensions as my 305 version with the exception of 8 bolt mating pattern to the crankshaft. They used the 6.2 Diesel ring gear, it is 16 inches in diameter with the same tooth count. I can tell you as of just two weeks ago it is working just fine. LMC is most likely clueless of the existence GMC V6 engine specially in pickup trucks. This is the type of part that you'll need to get from the dealer or at a NAPA auto parts. Pete Chronis Northern Cal 68 GMC KM-2500, 478M V6