904 to 727 swap compatability

[Justin Crossland]

Slip up under there and work it out. It will fit.

I recommend just building the 904. They are real easy. You can throw a rock and hit a build thread on them.

It won’t fit at all, the 727 has a larger input/ output shaft and internals. Beefier tranny, same housing. Im in the middle of this exact swap on my 88 d150, TQ grenaded so i got a 727, driveshaft needs shortened about 3.8 inches(guestimate) needs a 727 specific 2400-2800 stall converter, and a new yoke, depending on the year and model you may be able to get away with reusing the Ujoint.

 

[Justin Crossland]

A 904 built properly can handle 400/400 no problem. We run a '66 Cuda, 10.90sec. @ 119. I do mean PROPERLY! Stock parts work initially but will fail and when it does it won't be pretty. IMO, use the 904 with heavy duty parts.

So build a 727?