I have an aluminum face plated 18 spline a-833, a Lenco ST-1200, and a G-Force GF5R soon to be on the way.

I think the 18 spline is a ticking time bomb situation in a heavy car with a street friendly clutch and a stroked big block. Don't get me wrong I love my a-833's but have broken some stuff as you would expect. They are fairly light, relatively inexpensive and could not be easier to install being stock stuff.

I ordered a Lenco ST1200 last year around this time and am still waiting on the correct input shaft and an adapter that works with my Lakewood bellhousing. It's a cool transmission but a few factors have caused me to move on.

You will for sure need to heavily modify the tunnel and torsion bar crossmember to fit the Lenco in a stock floor car. IIRC it is about 8.25" in diameter and 28.5" OAL on my 4-speed. I am also concerned about cooling the Lenco on the street. Not much data on these for the street, especially on the internet. Who knows, maybe it will still get used in something, some day.

My reasoning for replacing the Lenco ST1200 with a G Force GF5R was simply (marginally) driveabiliy. Having the ability to downshift in this part of the country is nice for starters. Also, as Joel said, the ability to choose numerically big gears for 1st-4th gear to compensate for highway friendly gears that allow 5th gear to be tolerable at 70mph. Add in the H pattern shifter and it doesn't seem too far fetched for a street-strip car.

I'm not 100% sure what it's going to take to put the GF5R in my Charger but we can assume that the tunnel will need a few incisions and welding will be required. Hopefully cutting the torsion bar crossmember will be avoidable. To simplify things a stock configuration Lakewood bellhousing will be used so that takes care of the clutch linkage. I'm still not 100% on what to do for a speedometer.

I'll be interested to see what you guys are doing with these aftermarket transmission installations.