switching from 904 to a A500 or A518, anyone done this?

BigBlockMopar said

I did the 904 -> 518 swap.
Although I wished I had used a 500, they are hard to find here.
The 518 is a heavier transmission (internals) and that has an effect on mileage.

LockUp or Non-lockup is only a convertor issue.
I have used both types in my Dart without issues.
The Lockup-version comes closest to a 5-speed transmission.

I'm running a non-LU currently with 3.55 gears in the rearaxle.

Click to expand...

The Non-LU would have an effect as well. The internals likely do affect mileage as well as performance. (904 transmissions are quicker in the same combo) The gravy is that while basically all 500s are LU- they also all have the steep 1/2 gears. 2.74/1.54 as opposed to 2.45/1.45.

500s can be a bit hard to find- but it's worth remembering that while the 518 was always the 46RH/RE the 500 was the 42RH/RE, the 44RE, etc. 6 cyl overdrive trucks- especially Dakotas are also potential 500 donors as well as 6 cyl vans if so equipped. 6 cyl as in 3.9 so the Chrysler-designed bodies would be a safe bet 6 or 8 cylinder if OD- I think they also put 500s behind Mitsu motors and that wouldn't bolt up to an SBM.

What I've been much more intrigued about seeing is the possibility of using a standalone controller (especially the merits/complexity of a Megasquirt setup) on a 545RFE to go behind an SBM.