1995 suburban 8.1L swap?

[smithkid1996]

ok, so i really want to swap a 496ci 8.1L into our 1995 chevy suburban 2500 454 tbi 4l80e, and 4x4. from everything i have read it will bolt rite in with no mods the the engine mounts, frame, or trans. how true is this? i know it will need a new ECU, wiring harness, and all of the wiring. also, how hard is it to swap the dash to a slightly newer year? (probably a 1997 dash? all though i would rather newer) and is it possible to do the entire engine swap and rebuild the trans, transfer case, and differentials for under $5,000? i'm doing most the work my self, so it shouldn't be to bad. i am looking at buying a used engine, and striping it down to the block, and i have talked to a ton of old school hot rodders, and know how to get TONS of power and keep most of the engine internals. all the interior lights will work, rite? what about the fuel pump? will the old 454 pump work, or will i need a new one? would all of the old AC controls still work? would 15MPG be a realistic MPG goal? does anyone know how hard it would be to swap a late model escalate or denali seats in it? i'm not doing any upgrades that don't help the MPG's, either way, it only 9MPG rite now, so it can only get better, rite? also my father is SUPER light on the gas pedal (he will be mostly the only person driving it)... i have heard a lot about some marina parts? can someone enlighten me on that? is it a different engine all together, or just computer parts?

we are buying and selling tons of cars soon so will be towing trailers on a weekly basis, that's the reason for more then doubling the power in our truck (not saying much, the TBI454 only has 235hp, but 420tq...)

sorry for the million questions, but i want to know what im getting into. im only 15 and a half, but work on cars a ton, and this seems to be just about the easiest swap possible, and it would help a lot... plus its so much more power! lol

thanks

PS: looking to start this project ASAP.

hmm, would a duramax be an option? i mean, i will not have the cash to upgrade it, but you can pick up a remanufactured engine for 4500... will it bolt up to the 4l80e? i think it will... how hard would it be to do the engine mounts? would those bolt in also?