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Discussion Starter #1 (Edited)
I intend to update this as I obtain all of the needed parts to mate the two.

LandCruiser trannies included for this tech: H41 4spd man., H42 4spd man., H55F 5spd man.


(4 speed H42 transmission shown - http://www.cruiseroutfitters.com)

There are at least 3 "common" options for mating the LandCruiser transmissions to the 4BT block.

Using the "GM" adapter plate on the back of the 4BT options:

Advance Adapters GM conversion bellhousing - Part# 712532
Marks4WD GM conversion bellhousing - Part# 713024-EK
Downey Offroad GM conversion bellhousing - Part #331F4

Using the "Ford" adapter plate on the back of the 4BT options:

Advance Adapters Ford conversion bellhousing - Part# 712526
Marks4WD Ford conversion bellhousing - Part#713025-EK

*Disclaimer: I have not performed ANY of these conversions, yet. Research everything yourself, and double check everything. While I know the AA part# 712532 will work, I don't have the clutch/flywheel parts identified yet.

More to come...
 

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Do you know the shaft centre-centre measurements for those toyota boxes?
It's a good way to compare the strength. Bigger measurement = bigger gears.
 

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Discussion Starter #3
Do you know the shaft centre-centre measurements for those toyota boxes?
It's a good way to compare the strength. Bigger measurement = bigger gears.
Not sure what your asking for... "shaft center to center measurements"? Draw a pic if you can and I would be glad to measure them.

As far as the strength of the LandCruiser transmissions, they are very stout and hold up well to diesels and gassers alike. I've seen them run sucsessfully behind big block gassers, and torquey (sp?) diesles including the 4BT setup. They are similar in design the the timeless SM465. These trannies were produced from 74'-90', with minor changes.

Running one in a non-LandCruiser application? Well, it would really be pointless, you would have to custom design an adapter to mate them to any non LandCruiser transfer case, and to run them in a 2WD setup would also require a custom design. One could run the LandCruiser transfer case, the later model units 80'-90' are again bullet-proof units (all relative to a 6k lb vehicle). However the issue with doing so would be the offest front and rear outputs (parallel), thus it won't work with a standard center differential.
 

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Not sure what your asking for... "shaft center to center measurements"? Draw a pic if you can and I would be glad to measure them.
Hopefully this description will help, otherwise I'll try a picture.

Your normal gearboxes have the input and output shafts inline, below that is the intermediate shaft which is used in (normally) all but 4th gear which is straight through.
The spacing between the main shafts and the intermediate shaft gives a good indication of the size of the gears. Landrover even used it as a gearbox model designation for a while.

Some examples.
Landrover LT77 = 77mm centres, essentially a car gearbox.
Landrover LT85 = 85mm centres, reasonably tough.
Landrover LT95 = 95mm and tough enough for the aussie military.
Isuzu MSA box = 97mm, used in light trucks up to 7000kg loaded weight.
Isuzu MXA box = 100mm, replacement for the above.

Some of the landcruiser boxes chew out fifth gear quite quickly behind the 1HZ 4.2L non turbo diesel, but I'm not sure exactly which model gearbox.

It'd be good for comparison if someone could chip in with the measurements for the US boxes if they know. Shaft centre measurement isn't the whole story of gearbox strength, but it's a very good starting point.
 

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Discussion Starter #6
So I picked up another form of adapter today, its a GM small-block to SM420 bellhousing, with a custom adapter mating it to an H42 (so an H55F would fit too). I havn't split it apart yet, but it looks like it uses a custom front transmission bearing retainer. I've seen them in the past, they obviously work as there are alot out there on rigs. While I can get a new adapter for ~$400, this might be a good "demo" unit?

I've sourced the elusive GM manual trans flywheel for $450, add a clutch and I now have an assembled drivetrain :cool:

Cons: This is a 3/4 bellhousing, meaning the bottom is open, not a bad thing entirely, but not as strong as a 360* bellhousing (available from Downey). I can fab up a cover easily enough... Is there a reason other than random inspection that I would want the 3/4 bellhousing? I've got 3/4 bellhousings on my other Cruisers, I've never taken off the bottom cover since assembly.

Progress is progress...
 
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