I've looked into going with a NV4500, but it's just more work/money than it's worth given the $1000+ starting price for a used NV4500, and I would have to track down the elusive PSD circle pattern 205 since my oval race track 205 would not work with the swap. When I get done with the 5.3 LM7 swap in my 67, I will be tracking down a 6.0 LQ4/LQ9 to put in this one, keeping the SM465 4 speed.
Thanks! It wasn't me though, as far as I know this truck has never seen a state line since it was delivered from GM, and the 10mpg and no O/D doesn't tend to scream Road Trip! to me.