Looking for advice on a blueprint engine.

I am working on that, I Kinda want to stay with the 350 so it dosen’t have the kick down cable.
If you're changing transmissions I'd recommend something with an overdrive. We're putting a similar engine in a Camaro this winter and my buddy is going with a 700R4. It's an easy swap and is going to allow him to use a little more gear for around town fun and still be able to take it out on the highway. Just my two cents...