Kind of late to this conversation...
There's a company named LA Sleeve that makes progressive auto sleeves in a huge number of sizes. You could probably sleeve it to 95+ mm and still have a fairly thick wall sleeve. I've looked into both wet and dry sleeves and wet sleeves don't seem to be worth the trouble.
Now as best as I remember, the 1UZ uses 147mm rods with 52mm rod journal and 32mm compression height. Grinding the rod journal down to the "Honda size" 48mm opens up a LOT of rod possibilities (it's the now-common size in Nascar engines, not to mention the Honda H, F, and K series engines) and allows for the possibility of 4mm extra stroke. Or, you could take it a step further and go to a 45mm journal, same as the 4g63 (and most Honda D and B series engines) for a possibility of an extra 7mm of stroke. The 32mm compression height gives us a little room to play around with the pin by moving it up a few mm.
If it were me, and in fact, if I ever finally get a 1UZ this will be the course of action, I'd grind the rod journals down to 45mm, use two sets of stock 4g63 rods, and move the wrist pin up 5mm to utilize an 86.5mm stroke. While I haven't looked deeply into the sleeving bit yet, a 95mm bore and 86.5mm stroke will give 4.9L (and a set of 4 sleeves is less than $400, so I'm assuming a set of 8 would be less than $800). This would be an extremely rev-happy, 10k rpm potential engine though, so there'd be a lot required on the head to really utilize the max potential of the engine.
Or, for someone looking for max stroke using that same basic simply setup, 89.5mm stroke would be possible moving the pin up 6.5mm (still possible, I believe). With the same 95mm bore, you'd get a slightly less rev-happy 5.1L.
Of course, the benefits of doing it this way are utilizing the stock crank (cheap) and
utilizing stock 4g63 rods (cheap AND strong, not very heavy either). And you'd get a good R/S ratio and still maintain decently low piston speeds for high rpm. Even with the stock sleeves, which I believe could support an 88.5mm bore, 4.4L would be possible.
I beleive something like a max of 97-98mm bore is possible, so we're potentially looking at 5.4L, for a relatively "budget" setup. The nice thing about going to a larger bore is unshrouding the valves, and also the chance to work the combustion chamber a little bit and add quench to the pistons. The stock 1UZ pistons aren't exactly optimal for natural aspiration.
If you want to look at some interesting piston designs, check out
this page. Larry sometimes catches flack for his controversial ideas, but then again, it wouldn't be interesting if it wasn't controversial. Personally, I think everything he explains pretty much makes sense and I'm looking forward to utilizing a design very similar to his in my next engine. I'm sure he can custom make a set for just about any application, too.
Also check out his
head work for some pictures of some really NICE porting.