So I bought an 87 Generic Motors 3500 Dually Yesterday with a Rollback Bed on it. My plan is to strip the Chebby Drivetrain and Body, and replace it with my 68 440, and NP435 4 speed, and put either a 74-93 or 94-05 Cab and clip on it. Now my question is, has anyone ever used a GM PTO Box on a NP435 Tranny? I believe it's a Chelsea, but I haven't degreased it yet.The mounting bolt holes look the same I am just concearned with the drive gear meshing in the tranny. Thanks for your input!