[Farmall] IHC truck and tractor

[Rob Johnson]

I have an Inter truck , an ACCO 1710A twin cab with a 392 and Allison 451 (it has a PTO drive).
I want to set it up for the road , I was thinking of going to a later Allison , with 2 "locked " gears , and a 2 speed diff , and whatever engine mods seem appropriate.
I'm also on the hunt for an ASM or an SAW6 , or a AW7 , if they are still to be found.
I am using a W6 , with a retrofit AW6 3pl on it , which is just adequate to pick up a Wallace 5 tyne aerator with seed box.
But the tractor cannot pull 5 tynes mostly , and sometimes even loses traction on 3 tynes. It is on 14-9x 28 rear tyres , and wheel weights on cast centres.
I'm hoping that a slightly larger back tyre on a tractor with an "S" motor would do the trick , but should I go for radials ?, would that give me that extra bit of traction ?.
I want to stay with petrol engines , so that limits me somewhat .
Any suggestions?.
Rob J.Australia.