HOW TO CONVERT FROM 4G93T to 4G63T
Get an Evo 1-3 left front drive shaft, the drive shaft mounts to the back of the engine and the mount is different to the GSR.
You need an Evo 1-3 engine mount , note there are 2 pieces to it, the part that mounts on the block and the part that mounts to the car, you will need both. This will eliminate having to cut the VR4 mount and also the wrap around in the front of the engine. You will also need to grind some material off the bottom of the mount, the part that attaches to the car as it will stop the water pump pulley turning!! Also need evo plastic cover, the evo engine mount sits through the cover at a different place. Can use VR4 one, but you will need to cut it.
If using the VR4 engine the throttle body wires need rewiring. The colours are Green/Black to Black, Green/Red to Green/Red, Green/White to Green/White and the Yellow/Red wire is left unconnected (unconfirmed). If using EVO engine it doesnt need rewiring.
If its a VR4 engine the Cam/Crank angle sensor will need to be rewired, totally different plugs. These are the colours that go together, red to red, white to white, black to large black, yellow to small black. Only Evo 0 VR4 engines have the same style cam/crank angle sensor as the Evo and GSR, so no rewire required.
Use the upper VR4 radiator hose, just cut a bit off it to shorten. As for the bottom hose, I cut a GSR one and joined it up. An evo one may fit, but I went cheap. I have found there are different places that the radiator hose exits on engines, so this will also depend on which way your engine is.
The VR4 coil packs will also not plug in, just use the GSR ones and plug them straight in, just run the leads to the plug as indicated on the mounting plate for the coils, same as GSR anyway. Also use GSR ignitor.
Alternator wires will need to be lengthened, this is a piece of cake. I tried making up a custom mount for the alternator on the opposite side of the engine to sit where the A/c pump use to, but in the end I found the area too tight to work in with the engine in the car, so gave up. If you go this way, make sure the alternator is mounted as close to the engine as possible, or else you will run into clearance problems with the chassis as what happened to me (there are alternator relocation kits for 4G63's on EBay in America)
The exhaust will need to be lengthened slightly due to the longer stroke of the 2l, making the manifold sit higher.
Use the VR4 or EVO flywheel, clutch and pressure plate and starter.
This guide assuming your using the GSR gearbox.
Also, if your not gonna have the aircon pump and bracket on the back of the block, you need an 8mm spacer between the block and the hanger on an Evo half shaft, or block and one of the bolt holes on the VR4 hanger (it sits in a slightly different place). If you are gonna use aircom. the aircon wiring and hoses will need to be redone and regassed at your local aircon dealer to suit the 4G63T.