For the comment about needing a mechanical speedo passenger drop NP241 that narrows it down quite a bit more as I believe they were only made for one year.
The impression I got about the post for needing lower axle gears would be on the road. I've always said that axle gears are more geared (pun intended) for optimizing driving on the streets in 2HI. The thing with the 700r4 is the tall OD gear, and even with 4.56's it could be a struggle to turn 38.5's in OD. This would be the equivalent running 3.20 axle gears in a non-OD truck...and I don't think anybody is going to recommend that axle gear for 38.5's. I have 4.10's and have run 33" and 35" mud radials (relatively light), 13/38 TSL's, and now 39.5x15 TSL's. Even with only 33's the OD was only used once cruising down flat roads over 50-55 mph, 35's it became freeway use only, and with 38's I never used it even running 65 mph down the freeway.
The impression I got about the post for needing lower axle gears would be on the road. I've always said that axle gears are more geared (pun intended) for optimizing driving on the streets in 2HI. The thing with the 700r4 is the tall OD gear, and even with 4.56's it could be a struggle to turn 38.5's in OD. This would be the equivalent running 3.20 axle gears in a non-OD truck...and I don't think anybody is going to recommend that axle gear for 38.5's. I have 4.10's and have run 33" and 35" mud radials (relatively light), 13/38 TSL's, and now 39.5x15 TSL's. Even with only 33's the OD was only used once cruising down flat roads over 50-55 mph, 35's it became freeway use only, and with 38's I never used it even running 65 mph down the freeway.
