i need to figure out the following:

i have a Buick 3.8 v6 and 700r4 trans in my truck, which is probably of similar dimensions (i dont think i have seen a Chrysler one up close)
mine came out of a holden, so was already set up for rwd.


what transmission can I use? I am going from transverse mount to longitudinal mount unless I can find a wrangler with the engine I want and low (ish) miles.

What trans does the donor have? If you get a basic auto, like the 700r4, or manual its a bit easier as otherwise you will need the trans computer set up as well, or a standalone trans computer.
Are these engines ever converted to longitudinal? hopefully the bellhousing bolt pattern is the same as or close enough to use a common trans. Otherwise you will need to go thr route of a bellhousing adapter (get real good with measuring and cad one up for laser cutting) and then figuring out what flywheel, clutch, bearing, and spacer combo will get you working.
you will probably need a new trans crossmember. mine is just a 10mm plate cut to fit between the frame rails with the holden transmount welded to it (also had to relocate the handbrake pivot)

can I use factory motor mount locations?
Probably not, but i havent seen the engine. Mine has custom engine mounts welded to the frame slightly ahead of the mitsubishi ones, you will have to sling the engine in the hole and see how it goes. making engine mounts is pretty easy, you can weld right?

will I need to change up the oil system?

Depends what the sump looks like, mine has been notched to clear the crossmember. i think rear bowl sumps are available for the buickv6 in the states, i should order one and find out one day. So be on the look out for a rear bowl sump for your engine, otherwise be prepared to cut and weld it till it fits. The oil pick up didnt need to be modified in my application

will I need a bigger radiator? I know the wranglers had issues with that which is why I want to avoid a wrangler if I can.

My swap uses the standard radiator with the inlet and outlets moved. It handles the heat fine and would be better with a decent fan set up. The d50 rad it the same as what came out in the turbo mitsubishis of the same era, and they cool just fine. A truck i got some parts off had a twin turbo buick v6 and apparently that cooled just fine as well.
can I use the factory 3 liter v6 exhaust system and headers off a wrangler? I like that option alot.
Mine uses factory cast manifolds, they are quite tight to the block and only just clear the power steering box. maybe they fit, maybe you have to cut them up. I doubt the system will fit in nice. If you get it "free" i.e you go out and buy a whole donor truck to do the swap with (which is a good idea) then it may be worth your time to chop it up and get it to fit.
Honestly though its pretty cheap to either make your own out of mandrel bends, or have one bent up at a shop. I think my exhaust system is 3"

what about an engine tune? that would be cool and just keep it 'beefy and factory looking its not gonna be factory I just want it to appear that way to the average Joe dirt and the average car enthusiast.
Depends if you are going to use the factory ecu or not. If you get it with the donor car then its cheaper. But if its got a built in body control module that you are going to have to bypass to get the security to let the engine start it may be a pain in the ass, hopefully theres a tuning community for that engine and ecu? Otherwise a megasquirt is a nice project and you can do endless tuning quite easily. Keep an eye out for a used LINK going cheap, they are great too but a bit more expensive. My truck uses the GM808 ecu which has a great little tuning community and someone has already done the hard work in decoding the binary code into a user friendly PC program, you have to take the chip out and burn a new tune into it for each change tho, not as friendly as plugging a usb in

how about fuel capacity? I want to build a bigger tank so that I can go further but if I can't use the 3 liter exhaust I might go dual exhaust. I was thinking if I ever had to I could expand my fuel cell to go under the cab slightly and off to each side a bit extra and possibly reach 18 to 20 gallons???

Mine uses the standard fuel tank. Would be nice if it was bigger but hasnt been a major. Personally i dont think v6's sound great on a dual exhaust, i think you could fit a dual system in without moving the fuel tank tho. There plenty of room under the truck to mount an aux fuel cell
I know I need to build a tank to fit the fuel pump in it.

not really. mine has been running on an external pump for 20 years, just plumbed into the factory tank with a return. you planning on drifting this or driving it hard? if you are just doing normal road/dirt road driving then the factory fuel tank is fine. My system admittadly is perhaps outdated, if i was to do it again i would just add a swirl pot. so an electric lift pump to a seperate say 1gal tank that has an internal pump in it. Alot of guys run that set up now days and it stands up to hard driving

could I just buy a whole mini van from the junk yard a tear through it and build it and run it in mickey the ram 50?

Getting the whole donor vechicle is ideal if you are able to. This way any little part you forgot is right there. You can sell off the rest of the parts to get some cash back. Plus this will give you a whole loom to mess with

I am open to any suggestions but I am headstrong on the 3.8L V6 idea, it has a 60 degree Bank so it will fit well for sure and I can fabricate parts and all for it to make one hell of a truck.