+1 to what Pope says: I vote for the 3.0 swap
cheaper definitely since all you need is a donor 3.0 truck .. lol
buy a rusted out truck (or Mitsu Pajero) for cheap, strip, then recycle the carcass..
or sell yur truck and buy a 3.0 truck
I suggest doing the swap in stages:
1. swap in a stock 3.0 and get it running properly and all bugs worked out
2. add CAI
, exhaust, etc (basic 3.0 mods)
a good running, mildly modded 3.0 will feel like double the power of yur 2.6 ..
3. then adding a turbo and a standalone like MS
will be straightforward,
and can get 200+ Hp with no internal mods..
was there a 3.0 RWD 5-speed ? cuz that would be the sh*t in a D50 ..
either way ,
if the auto trans is based off the 904/500 then it will easily handle the power of a turbo 2.6 or a turbo 3.0 ..
[I see the Mazda 2600 also used the mitsu 2.6 '86-89]