While I had the Avenger apart I borrowed racerone3's spare T20 to see if it would actually fit in an Avenger. It does fit and it wouldn't take much to make a simple mount for it. There are really three challenges with this:

1. The intermediate shafts on the Avenger will have to be splined further to the outside of the Avenger so that the sprockets can slide over far enough to line up with the output sprockets of the T20. There is enough room for the sprockets to slide out though so the frame wouldn't have to be modified.

2. The driven clutch on the T20 sticks out, into the floor of the Avenger so you would have to cut or remold the firewall to allow the clutch room to work. It looks like the firewall could be remolded but that would eat up a good bit of the already precious leg room.

3. The gearing may have to be changed. The T20 has 6.25:1 ratio compared to this Avenger's 3.35:1 high and 5.15:1 low gears.

Just wanted to throw some of that info out there in case anyone else was wondering if it would work. I was pushed for time during this rebuild. If I had some more free time I probably would have made this work but for now I am going to run the stock Avenger transmission.