Hi I'm Kyron and I have a 53 suburban I just bought and am fixing up for a daily driver. No engine in truck but looks like motor mounts are installed for sbc 350. I was thinking of putting in a 700r4? What do I need to watch out for? Will I need new gears in rear Ended? No trans in truck but the guy said it came with a 4 speed. Any advice/tips is sincerely appreciated. Thanks