727 modifications .....

Yep you should be OK, sorry I missed it was a new trans... But still they tend to be on the loose side, that said you should be OK?

The pistons for low-reverse break with high line pressure and or a worn case and or piston. since you have all new parts and only are using a TF2 you should be OK?

But if it wa me I bet you have the crappy flex band and less than 12 springs in the front drum too.

I would make those minimum changes while it is out. Get a 4.2 lever, a better band apply strut, block off the accumalator, and go with 12 springs in the drum if you have the tools to take it apart? It will allow for a quicker apply and release for 2-3 and 3-2 shifting.

Enjoy...