Anyone want to talk Chevy! LOL

It's funny how out of touch I've got with the Chevy World. I have a customer who I'm helping just kind of refurbish an old car. It's a 1968 Chevy El Camino with a 307 2-speed Powerglide and I would like to know what gears it may have had? We're doing all the simple stuff like redoing the brakes the fuel cell and the front suspension needs plenty of attention. The motor had good even compression all the way around cranking compression that is. We took the motor and tranny out yesterday and of course it was one of the sludgest things I've ever seen on the inside. Our plan is to throw a small cam at it and clean it up and dress it up nice and clean. Put in Edelbrock intake and 4 Barrel on it. And some cheap Summit headers. We're looking to do a general cleanup and safety revision.
So obviously we're not going to do much performance besides the four-barrel headers and Mild cam. Maybe some valve springs and we'll definitely pop the heads off and get a complete reseal kit and get things cleaned up. Maybe a little Port matching maybe not. Our plan would be to build another motor over the next winter for any serious effort. Although his plans are for no serious effort but for some really cool looking hot riding stuff for the most part. My questions become in also using that 2-speed Powerglide? It seems a great thing to have for drag racing or something but for a guy just wanting to Hotrod around town and maybe cruise to the coast I'm thinking of 350 turbo or would fit him better? But then again I don't know how this operates with what kind of gears and all that stuff too?