Engineering Question

[williamlowe]

We cast and machined our own adapter plate (out of aluminum) to go from the Duramax to an SAE #3 pattern (in this case on a Twin Disc marine transmission). We want to double check our dimensions by finding out what they are supposed to be. We have measured other blocks with the standard Chevrolet bolt pattern and they all seem to vary quite a bit.

[More Power]

A TH400 or 4L80-E with a Chevy/GMC V-8 bolt pattern will bolt up to and work with the Duramax 6600 (same torque converter bolt pattern as that used by the Allison as well). I've had TH400 bolted up to a Duramax, and GM Powertrain's Duramax powered Pikes Peak truck used a 4L80-E.

MP