Transmission shops

I have a transmission already that just needs a rebuild. I’m unsure of the inners and wanna make sure it’ll be a good trans once I start putting the car together

That's good. Is this going to be a relatively stock build or are you looking for something more performance oriented?

Unless you are building a high performance/ race oriented car, I would look at adding a Transgo 2 shift improvement kit, and take the transmission to a local shop that has the highest customer reviews on yelp and other places. You can also buy a very high quality rebuild kit and bring it to the shop you choose. They often come with special instructions to improve the transmission performance.

Also, adding a good quality torque converter matched to your car, horsepower level and driving style is always wise. So is adding a plate style transmission cooler. Let me know if you want the name of the shop in Morgan Hill.