I have an 82 GMC, the 350 blew up when I got it, so I put a 305 in at the time because thats all I had. I then got a 78 3/4 ton GMC with a 454, well I blew up the 305, then installed the 454. What a big damn difference Anyways, I put flowtech headers on it and the don't fit worth a damn it's a hair away from my front driveshaft, and rub's the leaf on the otherside. These are suppose to be for a 4X4. Oh, and it does rub the front D/S hard. So that was problem #1, here's #2 The flywheel was kinda ate up on the 454, so I bought a new one. It had a 400 trans behind it, but my truck has a 350 trans that I left in it. When I went to mate up the 454 to the 350 trans the T/C bolt would not even line up, so instead of pulling the motor again, I just grounded the holes out bigger (WISH I NEVER DONE THAT). Is there a special flywheel I need?? So far thats it, If you have read my other threads, you'll see, i'm trying to figure the best tire and wheel size now. Thanks all.