[Farmall] Slightly OT Inter truck gearing.

[Robert Johnson]

I am inching toward getting my Inter ACCO roadworthy and registered , and I am just wondering if anyone has experience with the 392 and Allison combination.
My truck has a 392 plus an Allison 540 and the diff is a 7-33 to 1.
It has plenty of get up and go , but is too slow for on the highway.
Here diesel is around $1-20 a litre and LPG is around 45 cents a litre .I intend setting it up as a duel fuel , and to do some head work on it , and put headers on it.
My Holden ute is set up this way , and I've got 580,000 mostly hard kms out of it so far.
But that won't help that much for gearing , so I thought of using a 2 speed diff , so I can use it in the paddock , or down the road.
Am I making any sense ?.
Any other suggestions ?.
Rob Johnson Australia.