904 rebuild- what all to include

I’m pulling the trans out of my Dart. 1970 318/904. Daily driver, 318 is near close to factory hp.

I want a reliable transmission that will be still be a daily driver but maybe twice a summer at our local strip for the memories to run against my son’s Plymouth. I’ve been reading a lot of threads here on 904s. I’ve rebuilt two 727s over the years and it looks like the 904 is pretty similar.

I’m looking for suggestions on parts that should be replaced but not included in the typically available kits to give me a strong reliable transmission.

As an example here’s a kit from Summit and what comes included. I’ve notice none of them come with the low/reverse band. Is this something that ought to be purchased? Sounds like a good idea to install a bolt in sprag while in the neighborhood. we live in a hot summer climate- separate trans cooler over plumbing it to the radiator?

Description: TCI Pro Super Transmission Overhaul kits consists of the parts necessary to facilitate a transmission rebuild, including gaskets, a seal kit, pan gasket (reusable type), performance frictions, steel clutches, bands, adjustable modulator and a high volume filter and drain plug kit.

Thanks for any help. I’m not in a hurry so I have the time to get what I need to do this right and make it last.