That still doesn't narrow it down much, GM used similar desighn on their axles in the '50s, exept Buick, which stil used torque tube to the early '60s. If the center section is a some what oval shape, that would be a '55-'63 Chevrolet housing, Pontiac and Olds were more round. I do know that Chevy and Pontiac both offered 3.7 ratios.


Bill Burmeister