As I get all the info gathered up, I'll update this post:
1uz engine specs:
Aluminum 6 bolt main block
Aluminum 32v heads
VVT-I Available 98+ in US markets
Drive by wire 98+ models
Bore: 87.5
Stroke: 82.5
Rod length: 5.7455
Displacement: 3968.72
Compression: 10.5
2uz Engine Specs:
Iron 2 bolt main block
Aluminum 32v heads
VVt-I only available in US with the Lexus line
Bore: 94
Stroke: 84
Displacement: 4663.54
Compression ratio: 9.6
3uz Specs:
Aluminum 6 bolt main block
Aluminum 32v heads
VVt-I only
Bore: 91
Stroke: 82.5
Rod length: 5.7445
Displacement: 4292.57
Compression ratio: 10.5
A few little things to note:
The 98+ 1Uz intake manifold (upper & lower) will fit onto the 2uz engine. Everything matches up perfectly.
The 2uz heads are the same casting as the 98+ 1uz VVT-I heads, however they are machined differently. (Caveat: I've not verified the 91-97 non vvt-i heads)
Cometic makes an available 98mm bore gasket for the 2uz.
2uz gaskets, water pump, timing belt, idlers all interchange with the 1uz. Although they are made of different materials, they all share the same parts.
2uz crank will fit in a 1uz engine. (I've verified this)
Rods are the weak point on these motors. I've seen quite a few broken in core motors. The blocks are nearly bullet proof.
Chevy 5.700 rods will work if you are willing to do some machine work:
Chevy rod specs:
length: 5.700
Big end: 2.000
Pin: .940
1uz rod
Length: 5.7455
Big end: 2.0465
Pin: .880
In order to make them work:
Machine .0465 off the crank. I personally would offset grind to pick up the extra stroke, but it's your call.
Machine .060 off the width of the big ends of the rods. (.030 each side)
Once done, you can use chevy bearings.
WHen ordering pistons, make sure you lower the pin in the piston .022 This will allow you to really increase the ringland thickness for you crazy people who like lots of boost.
An alternate option is to use offset bushings for the piston pins.
Some misc pictures, I'll include cad drawings of things I have when I get them finished out:
