What is the difference in the lenght, width and height of the two? Can I use a th400 for a mock up trans for building a crossmember?
THanks

 

the 4l80e mounts back farther than the 400, plus there can be interference with the floor where a 400 will clear-also, depending on the year 4l80e, the cooling lines come out in diff places-i have one of each, and at one time had them side by side to ck the diff-i have a plastic mock up case of a 4l80e, and an empty 400 case, was mocking them up in a 70 chevelle