Sorry to leave you hanging, it's been a rough week. This is going much deeper than I thought, so hear goes. I bought the engine, had a vibration, did not go away, but made it good enough to go on a road trip up north the following week. Came home and GM Performance said to have an EVA (engine vibration analysis)done. None of the dealerships would do it. Dealt with 8 local dealerships, GM Performance, GM Customer Service in Detroit, Regional Mgr out of Texas. Bottom line, no dealerships wanted it on their property. This is in a 60 corvette. I had already replaced/rebalanced everything on the front and back of motor. With the motor, differant Harmonic Balancer, and flywheel only, still vibrated. One dealer said he would "look" at it, if I spent about another $600 in GM parts first( in the GM paperwork, they gave gm part numbers for HB, FLywheel, Preswure Plate, etc, and he would not look at it unless this was on it). IN the same paperwork it also say's this is an internally balanced engine, and can use neutral balaced external items(not word for word). I had the car 3/4 apart already, and after about 3 months, got tired of the games, yanked it out. At this point, the warranty wasn't doing any good. Talked to Jeg's, and they said GM handles all of their warranty issues, their hands were tied. Took internals to local shop, and the pistons were out 8 grams, and even though the crank had earlier signs of being balanced to some degree, it was also out. I do not have it together yet, so the final verdict is still out. The motor could be driven, but starting at about 1800 - 2500 it had a noticeable vibration that needed to be fixed. In reagrd to an earlier post about what kind of cars these go into, everyone at GM that I talked to , said that I had such unusual situation, because the motor was in an old car. Yea, I guess you buy 502 bigblocks for your pickup all the time. My opinion, they found a way to sell these things, but don't have or want to back up any issues that come with them.
