I'm going to pull my 305 out of my 37 and I was thinking of putting a 348 in it's place. As you know there not much room in the old trucks and measuring the engine I would have to cut the firewall 3" and move it back to fit the engine which is no problem. My problem is my knees will be at my chest level since I don/t have any room in the cab. I don't want to extend the cab but I can't think of any other options.