I swapped my 350 for a 454, no problems. I used the 454 mounts that were on the block already and just bolted them to the existing mounts on the frame. No problems at all. Problem I had was the donor truck was a 4x4 and mine was a 2wd, so the headers didnt fit from the 4x4. All of the accessories, hoses etc bolted right up. Swapped both engines from one truck to the other on a saturday. I used my original radiator because it was already a 4 core,and the donor truck was a 76 where mine was a 81. Ill never regret the swap. Before and after pics included. The after show a dirty engine, sorry.