What components should be upgraded to support 400hp in a 92 K1500?
 

Hi guys, I'm looking to get into finally building up my 1992 K1500. It has a stock 5.7 and a 700R4 with 257k miles on both. The engine has been rebuilt once already, and I'm not looking to put a lot of new strain on an old rebuilt motor that's already been pretty beaten up. I'm looking around for an LQ4 or LQ9 motor and plan on hopefully making around 400 crank hp - not super crazy power. The trans I'll be going with will likely be a stage 2 700R4 4x4 from Gearstar transmissions, and I figure both ends will need some upgrading or added beef to withstand the new power. Considering just about everything on the truck has around the same 257k mileage, what would y'all say needs to be upgraded to hold that power level fairly reliably? Any recommendations on specific parts or brands to use? The goal is not specifically offroad oriented, mainly looking to update the drivetrain with some modern kicks.
Thanks!
~Ken

I'd toss a new locker/posi in the rear end. The 10 bolt itself will be just fine with that amount of power.

If you plan on going "fast" consider a new driveshaft that can withstand the high speed without you needing to worry about it.

You'll want a stronger fuel pump for sure as well with 400hp. Wouldn't trust the old pump and not even sure those trucks even come close to running the required 58psi that the LS based engine/computer needs.

I think the stock pump runs something like 14psi if I recall correctly XD
Not necessarily looking at going fast, I doubt it'll really ever see more than 100 tops, and even then rather rarely. I'd like to be able to cruise about 75mph no problem. That's just about the top range of what the gauges read though so driveshaft will go on the list.
Would transfer case be something to consider, or not unless I start having problems with it later? It's not like it switches back and forth very often but I'm not wanting to bust it either and kill the trans with the shrapnel.
Any recommendations on who to look at or not look at when shopping around for the locker/posi?
For the pumps, is there a setup out there that would fit in the existing sending unit?

Bump.