[soutthpaw]

I have found the 100hp to be quite smokey under heavy throttle, the 80 is a lot cleaner. going from 65 to 80 you will not notice much difference... the reason I suggested the 40 tow is it will pull just about anything you need without excessive EGT's I have the 80 dd modified for light towing and fwy towing and it works fine... the trans shift points and duty cycles are a bit different I think but otherwise there is not going to be a lot of difference... get the tow or the DD but not both in the same HP as you are wasting a space.