Some advice

I'd find out/nail down what he wants and expects from
his car.
Make him write it down.
You guys are all over the map with gearing and motor mods.
Build from the rearend forward.
A 3:55 gear with a 2200 stall behind a 300hp motor will blow the tires off from a standstill, chirp second gear and still be a
good daily driver.

Even a good running motor with no stall or gearing will
end up a dog that sounds good and drives like ****.