I have an auto from a 78 Jimmy 4x4 400 ci and am trying to figure out what it is. This may or may not have been the original - tranny housing has some red writing on it for repair date 9-29-xX and initials of repairer. One source said numbers should be stamped at a possible of 3 locations - this has nothing on any of those. The case has a big "K" cast into it on bellhousing, and there is also a "T" with "11" below it cast into both sides of main housing. I am assuming this is a TH350 from the pan - square with one corner cut at an angle. Vacuum mod is at rear of tranny facing to rear. No electronics hookups on it, so it isn't a lockup. Any suggestions on where I may find info or source to help me ID this hummer?