For trails and rock crawling i like the sm465.
After going sand drag racing 2 years ago with my manual, i toasted the clutch in a weekend. mostly from my clutch drops in 3rd gear, four low.
Last year i said screw that, i'm not replacing another 400 dollar clutch after memorial day weekend again...
So i nabbed a th350-np205 and built it up with a transbrake reverse manual valve body, and a 10" 4000 stall converter.
The auto is just awsome for racing. it feels like a slushbox in the sence that i can tell i'm not getting as much power to the ground as the sm465, but ultimately the th350 with the 4k stall is definately faster in mud and sand drag racing.
To try and be competetive racing with the stick i would have to do a big clutch drop and just hold one gear (3rd in 4 low). while i was getting smoked by guys with automatics clicking off 3 gears going up the hill.
Thats when i decided i had to build an auto for racing.
Since a th350-np205 and a sm465-np205 are the same dimensions, i swap back and forth between the two and the driveshafts bolt up to both setups the same.
I even leave the hydro clutch pedal still hooked up when im running the auto... That throws people for a loop.. when they see a clutch pedal and an automatic TCI cable shifter..
My auto setup consists of an SFI flexplate, 4k stall converter, th350-np205..
...and then i have my manual setup: flywheel, centerforce clutch, bellhousing and hydro slave, sm465-np205.
with a cherry picker and a chain through the trasmission tunnel hole, that makes it soooo much easier swapping trannys. i have it down to only a few hours to swap from stick to auto or vice versa.