I'm currently working on the getrag 250g.
clutch- The getrag uses a 228mm clutch disc while the 2zz flywheel and pressure plate are setup for a 212-216mm disc. I got a bmw e30 clutch disc which is 212x8.5 and a 10 spline input. and it works perfectly! The best part about this is, there are plenty 10 spline clutches in different configurations that are the same dimensions.
The pivot ball, release bearing shaft, and slave cylinder pushrod needs to be moved outward.
To make the fork parallel to the bearing and clutch fingers a 15mm spacer needs to me made for the release bearing shaft. This will ensure the bearing is parallel when disengaging the clutch and is not binding.
The pivot ball is a little plastic cone with inbuilt fork clip. Matt from the development labs (check out his abandoned and submerged r33 race car he is rescuing) has drawn me up a cad drawing to make an extension which will be stackable depending on what pressure plate i may change to down the track. For standard a 20mm extension will work.
The pushrod is just some allthread with a dome cap on the end. For the standard clutch and pressure plate this is fine, but if i do eventually change to a stronger pressure plate this will have to be revised.
The pilot bearing is a holden 304/308 item which gives the snout of the getrag 12.8mm of engagement into the back of the crank.
The belhousing to block will need to be doweled. The standard tolerance for runout of the clutch is 0.1mm. noting that the 2zz spins at 8500rpm, im not really willing to have anymore than that.. I'll also be using a scatter blanket just incase that input shaft decides it wants to let go.
I had a bit of a look at the bolt situation for the belhousing to block. I can see about 6 possible spots to easily connect them together, more if i make brackets.