Several have been fast with 727. As Bob mentions, the stock bell does not provide room for a real converter. This requires a 1/2" thick miplate and a GM converter shell. There are parts to do this. If you buy a trans to do this figure $7,000. If you are able it can be a lot cheaper.

If you want all Mopar and have the money it can be done.

Or make a call and in a few days install a turbo 400 with Mopar bell.