I purchased a 1990 GMC Suburban 4x4 this afternoon for $500. its not in bad shape, but has a rod knock. I have a line on another 350. I would have posted this in the Suburban section, but WE DONT HAVE ONE! ray: lol Anyway, my question is this: What automatic transmission was available in 1990? The Burban doesnt appear to have a 700r4, but instead the TH400. Am I losing it?