I casually found this thread, wasn't really looking for it but thought I'd respond with my experience because I have a Dellow Conversion 1UZ/2UZ to H55F kit, I ordered it from them a number of years ago. The 1UZ engine swap is common there and quite popular with hot rodders, Dellow didn't advertise a 2UZ kit at the time. The bell housing bolt pattern is the same between the aluminum 1UZ and cast iron 2UZ so I shot them an email and asked if they would put a kit together for me.
I know it's easier to swap a domestic V8 into a Cruiser, there is good support for that decision and for many it makes sense. Since my F engine was seized and the numbers didn't match I knew I had to re-engine. I decided that I wanted a more modern fuel injected engine, eventually wanting to do a resto-mod vs. a restoration, ICON style but with as many off the shelf Toyota parts as possible. I didn't want a domestic V8 in my FJ40.
Transmission wise I bought a new H55F out of the US, they were readily available at the time for about $2500 - the H151F not so much. Most of those were overseas, in questionable used condition, and hard to find. For me the other consideration was the transfer case, it's easy to mate a split transfer case to a H55F and go from there. I even managed to luck out and solve my park brake problems by finding a split t-case OEM park brake conversion kit at Specter Off Road (obviously not a problem with the 60 Series).
I didn't have any trouble ordering from Dellow, a little time zone grief, late night calls perhaps, but that's about it. I sent them the measurements of my H55F input shaft, spline count etc., explained that it was going into a Land Cruiser. Even though the H151F is designed to sit behind the 2UZ, they had no concern over the H55F's ability to handle the 2UZ. They commonly sell kits to mate "doctored" high horsepower 1UZs to Toyota car transmissions without reliability issues.
The kit arrived in a pair of cardboard boxes covered in a million stamps, I don't doubt that they went out of their way to get it shipped to me which may be why they are reluctant to do one-off overseas orders. The aluminum bell housing and clutch kit components are of good quality and the kit was comprehensive (I think the clutch parts are Exedy). The only piece of the puzzle left for me to figure out is to properly size a hydraulic release bearing - the clutch slave cylinder mounts to the side of the bell housing and it interferes with the exhaust header. This was the only thing that went kind of sideways with the kit; they mistakenly machined the cut-out on the bell housing for the release fork on the "wrong" side, it's set up for a RHD. The boss for the slave cylinder is cast into the housing on both sides, so it's not really a big deal to swap it over, but a hydraulic release bearing would make it easier to route the exhaust anyway.
Engine/ECU wise I stuck with an older non-VVTi 2UZ (for simplicity's sake with the non-chipped ignition key) out of a wrecked 2005 Tundra with ~40K miles on it (confirmed through the Carfax with the VIN). I paid $500 for it which included the stock ECU, wire harness, A/C compressor, P/S, air box etc.
Unfortunately life kind of got in the way of my project. I ended up moving, our family needed a bigger house so I lost my shop. My stock '72 40 is sitting patiently in my "new" garage with all the parts in storage in boxes. I'm working on getting a shop built at my new house so I can get back to my project...
