[homemade87]

All th400 came with a 32 spline . There is several trany company's making a 27 spline for the 400 . It was so you could adapt the the 27 spline transfer cases to the 400 for a stronger trans ( my guess the 87 was a 4wd , could be a 2wd w/proper tail housing) . This was popular for mud trucks . This trans you have has been modified with the 27 spline or it is not a th400 . It has been apart at some point and possibly with some upgrades for the truck it was used in .

If you are planning to use it one option you have if you know indeed it is a good trans is to change the driveshaft yoke and tail housing ( If needed , depends if they use it on a 4wd ) if the trans shaft is the same length . This may get you by for a while until you have the time to build the original . Yokes are less than a $100 .