[cleszkie]

Everyone will have their own opinion on what drivetrain combo is best. Here is what I run and why:

SM465/NP205/Gear Vendors OD setup behind a fuel injected 400 SBC - I tow heavy trailers and do a lot of travel in very remote areas so the SM465 is bombproof and will get you home every time. Yes it shifts like a dump truck. So it is definitely an acquired taste. The granny low is great for slow 4x4 ascents and for getting you moving from a stop with a heavy trailer. The NP205 is a bombproof cast iron gear driven case. Nuff said. The Gear Vendors gives me overdrive and allows me to split every forward gear. This allows me to cruise at 80mph and keep my engine in its rpm sweet spot while towing up mountain passes. I went with an EFI 400 SBC and not an LS because I can work on a SBC and know them inside out. I can't say that about an LS.

I should note that I run 4.10 gears with a 35 inch tire. This combo works perfectly with the overdrive, and allows me to run 4th gear non-OD on the highway when traffic speeds are lower. I personally think that 4.56 gears will be a tad too deep to get the full advantage of an overdrive if you want to cruise 75-80 mph with low rpms.