Hi Pilbara,
That's some good info, thank you!
Since posting this I've ended up getting my hands on a fairly new (2019, 110,000 kms) H152 box (taller 5th gear) from a VDJ79, so the scope has changed a little bit. That was taken with everything out during an auto conversion and came with a good HD clutch, flywheel and all the cylinders etc. That's all on a 14 tooth spline but since it's nearly everything I need, I'm now planning on swapping the longer 14 spline VDJ input shaft (too long to cut down) with a 14 spline HDJ80 shaft, machining the flywheel, popping in a new throw-out bearing and spigot bearing and using that set up as-is.
(This is basically the same route I'm taking as well VDJ79 H150 into HDJ80? - https://forum.ih8mud.com/threads/vdj79-h150-into-hdj80.1140821/#post-12395413)
I have the stock 275mm flywheel atm on the 21 fine spline shaft, but I believe the 300mm flywheel has the same radius, just a bigger friction surface. I would love to clarify that before I start buying parts..
(Not sure on this, that's why i went for the FZJ75 HD 275mm clutch.)
This does leave me without a transfer so far though. I'm now considering just swapping the input shaft (or shaft and gear - I'm not sure how to find out which input configuration I need, but I guess I have the full manual HF1A) in my current one as that seems to be otherwise fine (230k kms, recently pulled down by Cross Country for seals etc). I don't want to give up the part time set up.. I've heard mixed reviews about how hard this is to do for a handy novice, but so far it's leaning towards do-able, on par with the input shaft for the box - do you have any idea?
(Yes I think it is doable and straightforward, I would say that the input shaft changeover is a slightly more advanced just looking at my open H150 versus transfer cases I've worked on in the past.)
Figuring out the parts for the transfer input might be my biggest remaining mystery! I think this part below might be the key, but honestly I have no idea so I'm gonna have to make a phone call or two perhaps..
(This is one of those info gathering items for sure, I haven't even sighted my transfer internals on the R151 HF2A yet but discounted doing that shaft as the thought of another person driving my 105 and hitting the H4 button not knowing if the hubs were engaged or not frightens the hell out of me, at least with our HF1A transfers we can feel our way in and out of H4 gently and fast if we feel some rotating teeth growling at us, not so with the part time kits except for some clever lockout method I've yet to see.)
Transfer Case Input Gear suitable for Landcruiser VDJ76-78-79 HDJ-UZJ100 FZJ105
www.allfourx4.com.au
Which looks the same as this (I'm assuming is for my car):
Genuine Transfer Input Gear suitable for Landcruiser 105 Series, HZJ105, Manual from 1998 to 08/2002, Manual & Auto from 08/2002 to 2007
www.allfourx4.com.au
If you have any good resources for the input shaft swap on either box I'd love to hear them
I found this for the older boxes, but I figure it should be a good starting point:
I'm also not entirely sure what I'm going to run into when I try and mount all that back together into the car!
(I think you'll be fine, it has been done a few times with the Pov pack wagons but the GXL is loaded with oddities like height and position of the transfer shifter for the console, I'm having to use a HDJ transfer shifter arm but an 80 series low range lockout which requires a few mods to use a HF1A where the HDJ's are normally a HF2A, it's a bit of a pain but will work ok in the end, yours should pretty much bolt up from what I've seen, there is at least one Aussie user on here who did what you are doing. Hope this link is legal, couldn't see anything about helpful links in the rules here hzj 105 1HZ R151 to H151 conversion - https://www.exploroz.com/forum/103115/hzj-105-1hz-r151-to-h151-conversion )
That's a great tip about the bellhousing, I can't use the VDJ one so I'll bear this in mind when I'm looking!
This has been an info overload at every step, but I'm loving the learning curve and finally getting close to a solution, after being pretty overwhelmed at the start!
Hope that all makes sense, I've tried to be thorough for other readers also, but it feels like a bit of a brain dump too!
Please let me know if you see any glaring mistakes or incorrect assumptions!
(I face the same woes but it's getting closer to reality...)