There are 2 types of TH350: long tailshaft and short tailshaft. They can be interchanged, but the driveshaft length has to be adjusted accordingly. The crossmember and tranny mount might be different...I'm not positive on that.

Best way to find out if the tranny and driveshaft will be compatible is to measure both transmissions from the front edge of the bellhousing to the end of the tailshaft. It'll be immediately apparent if they aren't the same. The long shaft tranny is quite a bit longer.

I put an Offy intake manifold, Carter 625 AFB carb and Hedman headers on my 64's 292 motor. The 230 is pretty much the same motor, except that the block isn't as tall. You could use the same setup, but I'd go with a 500 CFM carb at the max (and maybe a 390) for the 230.

There are pics of my truck's "process" on my website. The url's in my sig.

Good luck with your project.

Ray
Enter the Chevy Asylum
"The Ugly Truck"