I'm in the process of making this:
It will replace that shitty bellhousing. I was going to make these adapter plates available to others, but the task keeps getting more expensive, so I have all but decided to pass on making more then one. I'd need to make 10 at a time to keep it affordable for others. (Down to a few hundred bucks) Basically it takes a DSM front wheel drive transmission case and allows you to bolt up the Toyota "W" series transmissions. These include the trucks, vans, celica and even Supras. Pretty much most of the rear wheel drives that Toyota made up until about .. Well until they stopped making rear wheel drive stuff.
I think the Supra (single) Turbo tranny should hold up well for you guys..?
I had a few people interested, but that was about it.
During Easter we took it out to Moab for a lot of fun. I ended up busting the cross pin in the Toyota 8" rear diff. This also damaged the locker, and I discovered that my ring and pinion were really thrashed also. So that was that. I'm getting ready to do the next stage of build up on the beast. going to get some new suspension, a longer wheel base, a better cage, better motor mounts, the new adapter, etc.
A little about the vehicle.. The engine has been VERY reliable. Clutch set up is pretty much all Toyota and it has great feel. The twin t-cases and 5:29 ring and pinion gives me a crawl ratio of a little better then 100:1. This means I can put it in first, low, low and with the clutch engaged (vehicle moving) I can get out and walk around the vehicle. Yep, this is a SLOW 4G63. The 37" MTRs do a very good job in the rocks, sand and highway.
I don't think I have gone much over 85 mph. Not that she can't, just that I rather not. The spring rates are very low on this vehicle, maybe 150 lb/in. My suspension travel is measured in feet. Your spring rates are problem over 250 lb/in and you probably only have 4-7 inches of suspension travel. Thus not a high speed monster. But get me on a nice dirt road, or a sand dune and I'm hitting the fat pedal for all she is worth. The clutch does start to slip when I get into boost (about 14 psi) when in a rather high gear in the sand. The vehicle is moving at maybe 20 mph, but the wheel speed is probably close to 50-70 mph. Can you say rooster tail? It's kind of like a big Quad in the sand.
About the biggest issues I have had since I got it running is with keeping the rear axle from twisting up from the torque loads. I have a large ladder bar installed to help protect the leaf springs from wrapping, but eventually that wasn't even doing the trick. Thus my new suspension plans. Will be going with a 4 link and air shox. Also installing a beefier Toyota V6 rear end.
Well that's about the highlights.. Let me know if I can help you guys out.
-Wayne