For your Cummins swap idea go here:
http://www.4btswaps.com/forum/index.phpI have seen a few of these 4BT swaps in old Chevy trucks, and I think they are a great idea. My 52 1 ton may get one eventually, but that's way down the list.
A 4BT is a smallish Cummins 4 cylinder about 120hp + or -, depending on how it is setup, same family as the dodge truck engine, so essentially 2/3 of a dodge engine. They are very common in step vans and industrial equipment.
One of the most important parts of an engine swap is gearing, particularly a diesel. You have to have the proper gear ratios and tire size combo to make the best use of the engine and possible fuel economy. So a rear axle swap and or transmission swap is also to be considered.
Grigg
