swap in a 13?

I pulled a 13 double over out .62 overdrive. After I built the big motor for that truck I couldn't get it to live. There are several upgrades for them but none helped enough. It also had a high low gear and a race car reverse that I always hated. The whole reason I wanted the aux was for that one extra gear. I have run a double overdrive since I started and just didn't want to give it up. You are correct my 13 is .73 and the aux is .81. I really think the back box would be more beneficial behind a 15 as it would let you split those last 3 holes on the 15. .73 turning a .81 is a bit much, I run in .78 turning the .81 most of the time I'm just slipping along.

Never driven it but there is a V8 CAT 359 with a 15 and a 4 at Mom and Dads gonna have to do something with one of these days. So I know the combination will jive.

 

I would look into it for sure. The rotating mass will be a little more, but honestly we don't drive these trucks for the awesome fuel millage they get. Lol pulling my hopper mostly with the red and black truck my average so far is 5.8 mpg. Course the straight 13 is pretty sweet in these trucks as long as it's a 9 series. It gives you something to think on for sure

 

I bet that is a little sweetheart. I think that unibilt set up is the best thing you can do for comfort. I was trying to remember what year they went to the dash of class (corvette dash) that was somewhere around 75. I think the 1100 series cab was around 73 I think.

 

Well Im thinking 11x24.5, 46k 4.56 Ratio, .73, .81, 1400RPM @ 65MPH? Only when Im 80K or less, when Im 110K I would keep it in direct.

 

The 4.56 will feel better for sure, only thing that would worry me is spinning them fast enough to create a lot more heat. But as with anything this is a give and take deal. I really don't think the heat would be that much of an issue if you don't mount wings on it every where you go

 

Can they get hung up if you don't make the shift right?

 

I have never had mine get hung up or locked in two gears, they gotta be pretty bad shape to do that. I have however got lost and had to stop and start over with the 6+4 setup