I ran a Nash several years ago. Those transmissions are decent for what they are but there are stronger more reliable manual transmissions available . If you're going to stay with that transmission faceplating it seems to be a worthwhile upgrade. You can go to
http://umtrdragrace.com/ and join the forum. There is a lot of good info there. There's more stick car guys there than you will find in any single place and they're very helpful.