An original 2 speed will have a faster ratio than that on the high side and could be an easy swap.
Grigg, isn't the 2 speed high gear about 6.11? That amount is so negligable to not even count.
Even if you do add the 261, I still don't believe you'll have enough added power to push a double overdrive.
What is it you exactly want this truck to do?
A 235 or 261 can easily go the speed limit or a little more with an overdrive.
Jeff
