As a lover of dentsides, and a notorious bad decision maker, how much do you want for that suburban?
I don’t think you are making a great choice here. An appliance is what you want for a tow rig. Excitement isn’t good when you are dragging a load somewhere.
But you seem committed to this already, so here’s my take.
-The dual fuel thing is cool, but can you get parts for it?
-Just go ahead and rewire the whole thing. You know it needs it.
- The rear is a Dana 60, right? If so I’d consider stuffing a 14 bolt under the rear. Spring perches and some driveshaft work will gain you a better rear end, more easily serviced brakes, and parts that are available everywhere. I’d shoot for 4.10s to make up for the smog era motor.
-E4od is a solid swap option. Expensive to build right, but they are big beefy units. You can hear horror stories about them in the 90s and early 2000s, but the aftermarket has figured out the e4od/4r100 shortcomings and any builder worth a fuck can build you a good one
-there’s not much to be done for power on a 400 without seriously getting into the motor. The factory heads suck, but what’s the point of putting $$$ heads on a stupid low compression bottom end? Then while you have the rotating assembly blown apart for new pistons, you might as well throw in a stroker crank. It snowballs quick
-33 gallon bronco tank to replace your rear one. You’re going to get single digit mileage, you might as well suck it up, drill a couple new holes, and try to get a 300 mile range out of the bitch
i'm probably going to list the suburban for $6,500 with most of that being due to the sub 20k mile motor. driver seat leather is worn, body has a dent in the rear quarter panel, paint isn't perfect, so i'm not sure i'll get that much for it, but probably close. I don't know what my bottom dollar is, but I probably won't take under $5k unless i'm right up against the wall in needing to move, or else i'll just give it to my dad or father in law. it's a great toaster.
the parts are all there for the propane setup, i'm going to check the lines eventually and the impco reseal/gasket kits are like $30.
the wiring is an absolute mouse nest
most of the stuff works, but yeah everything that gets touched will be planned on complete redo. broken up into small projects, figure it will get there eventually.
if I do a trans swap, it will be with junkyard parts. i'm not going to ever make enough power to hurt the OD trans and I figure it is likely the newer motors and their gobs of power that were causing the issues. but, O/D is just a nice to have
*one of these days* a turbo makes for an easy solution to the low compression issue. in my mind, the added bonus of propane means that likely some of the 50k miles (all original and no rollover, surely
) were done with propane which is much easier on the engine, so i'm hoping the bottom end is in better shape than a comparable straight gas motor of the same year.
i'll have to look into the 33gal rear tank. with the current two that both seem to work I've got ~42gal on hand, which is what the suburban has. I rarely spend enough time putting a full tank in that thing, not sure that going up to ~55 gal of gas would benefit me much.
stupid newb question; I've heard dentside, fleetside, highboy, are these all the same thing?
i need to practice for the inevitable real life "ya autta jus LS swap it!" or cummin's or whatever those other diesels are called 
are you keeping pictures and doing a thread on it here? i've never ventured into the jeep section
so buy the truck here, sell the other two here, drive to TX and probably sell the truck down there in a couple years when something else catches my eye