I am looking for an overdrive transmission that will match up to a 440 and fit in a 79 American Clipper motorhome, with minor modifications. The motorhome is actually based off a dodge van. Any ideas?

 

You can buy an overdrive to add onto your 727 (gear vendors, among others). They're pretty expensive, though.

I'm not sure there is an existing overdrive tranny that will bolt up to the 440 in place of the 727.

We thought about doing the overdrive thing on our '73 Concord 20' Class A with 440 & 727, but we usually tow and the overdrive will be useless. And it's quite an expense.