Gear Box Options for RB26 w/ 700hp

[Mitsubayati]

Background: I've searched for quite some time and haven't really been getting the answers I want. I plan to build up an RB26 single turbo setup capable of producing around 700hp. This setup will be placed in an S13 and be used strictly for drifting.

My Dilemma: I want to use something like a Jerico 4 speed or G-force transmission but finding someone who makes an adapter for them is close to impossible. I've researched transmissions that people do use currently and the hot seller seems to be an RB25 gear box outfitted with PPG dog cut gears. That's all well and dandy, but I have issues with that.

First off, PPG gear sets cost more than a Jerico transmission. Second, the RB25 transmission is huge. I know I'm going to be removing the transmission a lot and having a lighter more compact and easily rebuild-able transmission would be more of what I'm interested in.

My Question: Can anyone help me find or know of a local shop or a company that can make a gear box/gear box adapter for my application?