Since day one when I bought my MCSS I thought I had a 355. That is what the seller, who had it built told me it was. Shortly after I got the car I had the engine pulled to put new gaskets in it. I took several pics of the engine while it was apart but didn't research part numbers. I recently sold the engine because I am doing an LS swap. Both heads were leaking pretty good. I agreed to put new gaskets on it. When I got the heads off I found the #3 piston had a chunk missing. When I got the piston out it was a KB 134-030. In my research to figure out what type of piston I needed and the rod, crank PN I was pleasantly surprised to confirm I had a 383 and not a 355. I ordered a replacement piston and rings from Jegs on 1/9/20. With an estimated delivery of 1/28/20. The gentleman I sold the engine to (I kept him appraised the whole time) can't wait on the piston and informed me he wanted his deposit back. I didn't argue. I just agreed to return his deposit. He was getting a good deal on a 355 that I was repairing on my dime. I wouldn't knowingly sell a broken anything to anyone. Many months ago I started a thread where I was passing a vehicle and I suddenly lost power. The spark plug was not broken but was smashed. We all thought the damage to the plug must have been done beforehand and installed anyway. It looks like that is when my piston must have broken. When the car was in the shop I also changed from a 3600 stall to a cheap 2800 stall and attributed the loss in power to the TC. So I have been driving the car with a busted piston for several months. There were no symptoms of a problem except the substantial loss of power. Trying to do the right thing in making sure I wasn't selling a crap motor has actually turned out possibly benefitting me as a383 sells for at least double what I had sold the (355) for.
