Talking old school non electronic diesels, the Cummins is more efficient than the Toyota or Isuzu. They will be more powerful and use less fuel doing it. As mentioned above, the Cummins is loud. It might make your nice Land Cruiser feel too much like a tractor. I’d recommend riding in a converted vehicle first. You might not like it, or there’s a possibility it might put a smile on your face.
If considering a 4BT or Isuzu 4 cyl diesel, be sure to consider the largest drive train components possible. Due to the 4 cyl only firing every 90 deg of crank rotation, the torque pulses at the flywheel are as forceful on a 4 cyl diesel with only 230ft lbs of torque as that of a big V8 with 460 ft lbs of torque that fires every 45 deg of rotation. The long stroke 4 cyl diesel, even though it’s not a power monster, can flat tear up some light duty drive train components. I’d look for a tranny rated for over 400ft lbs of torque.
You probably already know overdrive is a must. The 4L80E seems like it might be stout enough. I’m going to give one of those a try in the future.
The most successful diesel conversions with the least amount of problems are the ones that use the same transmission that went behind the engine from the factory.
Many problems pop up with conversions. Some don’t surface until two years later. Examples: Why can’t I get the transmission to shift correctly at the right time?, Why does my motor seem like it’s revving too much for the speed I’m going or for amount of power going to the rear wheels?, Why does the pilot bushing wear out every two years?, why do the lockup clutches on my torque converter fail every two years, where are these new rattles or vibrations coming from?
I wish I could recommend some diesel conversion specialist down your way. There’s Stoney’s in south Florida, but don’t know enough about them.
Too much to cover on a post. Feel like talking on the phone, PM me, and I'll respond back with my phone#
Steve
