On my quest to track down parts for the manual swap, I ran across a 4 Speed Saginaw that had been rebuilt 8 months ago. It was in a stout 69 C10 that was coverted to automatic. Is this a decent transmission? Would it work with my 350 and future 3.42 posi rear? I am completely new to 4 speeds, I picked it up for $300 figured it's already rebuilt. After research: 3 Lines (grooves) 3.50 2.47 1.65 1.00 I just have not heard of these much in Buicks. I am still thinking of looking at an M20 if I run across one. Would the Saginaw be fine behind the 350 and future 455?