You just need to get a low miles sohc neon tranny from a junk yard, use your bellhousing, a couple external parts like some mounts I believe for the shifter linkage, etc..., and your done. Just make sure your making enough power to take advantage of it.

I got a tranny from a local junkyard with 40K on it and a cracked bellhousing for 100 bucks, then my transmission guy disassembled a blown tranny I had, and used what he needed from the eclipse tranny to couple it with the neon one for $100 bucks... $200 bucks and I was done... and all I did was pull it and put it back in

edit: and yea, it will help reduce wheelspin off the line somewhat... if your built and tuned... umm its just gonna spin anyways unless you have a good set of slicks on.

5th gear is purdie darn long now after the conversion... not really of any usefulness now other than top speed runs and highway cruising...

This is not a hard conversion at all, but I just don't do transmission work other than sensors, and diff installs, and it usually costs me 40 bucks for one of those cheap plastic bearing i always break when i seal the case back up anyways, heh

and no, no machining required, just plug and play. and my gas milage is umm almost non-exhistant anyways so i couldnt tell you if it changed, my guess would be you would be getting better gas milage from the nice longer 5th for hwy driving.