42RH / A-500 in a Duster with pictures.

=D>What a great thread!!!!!! I have been following this thread very closely. I want to also install the A500 out of my 91 DAK in my 70 DART. A Question was raised about the total drop in rpm at cruise.
IF I remember correctly the final drive ratio on the 500 was .69. The math shows for example that original cruise at 3500 would drop to 2415 which is a difference of 1085 rpm.
I don't remember exactly how much the converter lockup dropped it but it seems that it was 200 rpm at best. Grand total APPROXIMATELY 1285 rpm which would give a final ratio of .64 which for me would justify the expense .

OF course mileage is dependent on many other variables but I had a buddy with a Chevy truck who lost his OD and he went from 21 to 15 mpg.