wildcatjason
Full Access Member
- Joined
- Apr 7, 2012
- Posts
- 513
- Reaction score
- 11
- Location
- Kansas
- First Name
- Jason
- Truck Year
- 1988
- Truck Model
- suburban
- Engine Size
- cummins 3.9 4bt
Have you said what year step vans this set up is from??? I'm thinking the ultimate set up with this would be, low rear gears, like 4.10's, the 4BT and a 4L80-E with OD cuz I'm sure this diesel like most, don't like high RPM's. But imagine the torque with the 4.10's and motor putting out 410 ft lbs. You can get a stand alone OEM computer for the 4L80-E that came behind the 6.5. IIRC, and someone can correct me if wrong, 92 and 93 year model 3/4 and 1 tons got it.
The engines parallel with the 6bt as far as years. Mine is a 1990 block but it was in a 1986 stepvan. They are still using these engine today. They are just computer controlled. People who run low gears usually do with big tires. Even the stepvan i owned had 4.10s with huge tires. I don't recall the diameter. I wouldn't call the 4l80 the ultimate if your looking for towing and gas mileage. Yes it has an overdrive, but it also has a 2.48 first. The problem with getting a standalone from a 6.5 diesel is the torque curve is different. Some guys run a optishift controller to change the shift pattern on the fly. A 4l80 would be great in a comfortable suv you don't worry about shifting and pulling a reasonable size trailer. I like my 3.42 rear and my zf5. It has a 4.10 first with an overdrive. Some guys who run the nv4500 say the first is pretty worthless for daily driving. Allison 1000 is an option as well.