so i've been kicking around some ideas for either my K20, or its replacement in the drivetrain department. i've come up with a few ideas, i definitely want to stay gas powered, and i want to stay small block. the original idea that i had was a full roller 383, that should make somewhere near 460 ft/lb, and have a relatively flat torque curve. i found out yesterday that a local guy has a virgin 400 shortblock, so i plugged the extra bore size into my 383 formula, adjusted the SCR to achieve a good DCR. its low enough that with the Vortec heads i could safely run 87 octane, although i'd probably run 89 in it just for the little extra safety. what i came up with is a 406ci engine that will make nearly 500 ft/lb from 2000(lowest any of my engine programs will go) to 4000, which is where i'll be using this power. i'd like to stay auto. will a stock TH400 stand up to this kind of power? i'm also tossing around the idea of a 4L80E, as i'd like to knock down the gear ratio a little and drive the thing once in a while. will the 4L80E stand up to it?