I just acquired an 87 b2600 4x4, 5spd, which has the low-efficiency, low-power mitsubishi engine. Mine has a Weber carb with KN air filter, also has steel headers instead of exhaust mani, but no other mods. Runs reliably, just GUTLESS.

I'm thinking about replacing with something better, as the current 245k or so engine seems VERY tired (feels to me like its putting out maybe 100hp to the wheels), but can't have the truck out of comission for very long, and I'm not experienced at fabricating custom mounts or other parts.

Any suggestions on what would be a somewhat easy replacement/upgrade to put in place of my Mitsu 2.6l?

I guess another possibility for temporary fix would be to turbo or supercharge existing, but I've only done that on fuel-injected engines, and not sure of what implications there are for carb'd.

Maybe a newer 3l from a MPV or some Ford engine would not be too difficult to bolt up?

 

That was a Mitsubishi engine so one of theirs may bolt up.

 

My '92 B2600i is kind of like yours. It's injected rather than carbs and has the automatic trans and 4wd. Pretty zippy up to about 20mph then sluggish up to about 40mph then gets right out and moves. Cruises nicely at 70. I've always felt its the price I pay for the 4wd - it really is a heavy vehicle and those 4cylinders just can't make it do wheelies.

Rolomac