Both use a 91.0 mm bore.

The 4D55 uses a 90.0mm stroke.
The 4D56 uses a 95.0mm stroke.

It seems to me that I can buy a 4D55 here in the states and simply import the crank, rods, pistons...

The ONLY 4D56 I've see on eBay cost US$2500. It included an automatic transmission and transfer case. Messaged the seller and he'd cut me the amazing deal of US$2100 for just the engine alone. <img src="/forums/images/graemlins/rolleyes.gif" alt="" />

That seems a little more than I want to pay for a used, condition unknown engine...

Importing parts also will probably be cheaper seeing as how the block weighs quite a bit and takes up a lot of space.


Should I look into getting specific year parts? Perhaps one year has a better injection pump or something?

I want to use the distributor type injection pump rather than a common rail diesel.