[MrBeast]

To help keep your burb under control, I think the best place you can start is with the supension.

What I would seriously look at is bagging it, and instead of using a manual ride height control, use a semi style leveling valve, well not one but 4 of em, if you put one on each corner where 1 valve controls 1 bag, it will actually act as a sway bar, and it will work automatically to keep your ride height where you want it.

The next thing to consider is your rear end, a 3.54 ratio is ok if you are only going to be doing towing in flat land running a direct drive tranny, But seeing as how you live in the Rockies, I would seriously consider a NV4500 conversion. As well as swapping in a 14 bolt with a posi and 3.73's

The advantage of this is, you get an overdriven transmission that will help your millage, it is robust and dependable, and the best thing is, it has a stout granny low that will help lug the trailer around when you need to.

As far as your 402 goes, it just isn't a hay maker of a motor. You do however have a big block burb, that means transplanting a larger big block in will be much easier. I would seriously consider trying to find a Vortec 8100 or a 7400 454. You get the EFI that way with the big block power, I have had 2 of the Vortec 7400's great engines. I wouldn't hesitate to go with one again.

In your shoes I would seriously consider looking around for a late 90's truck that has the 5 speed manual and Vortec 454, this way you would get the 14 bolt, 454, tranny and everything you need in one shot. I have seen them for as low as 3 grand in decent condition, where the body was junkable but the drive train was good.

Also it is hard to tell but are you running an equalizer hitch? That will make all the difference in the world.