Any modern engines or engine builds for modern results?

I'm putting together a 340 with ported Edelbrock heads, Comp 222/230 .538/.534 lift hydraulic roller cam, drop in lifters, Super Victor EFI intake, FAST 4150 throttle body, & FAST XFI Sportsman EFI, backed with a Tremec 3550 5-speed. It's going into a 72 Duster 340 clone with 3.91 gears! Engine is at the machine shop. Hope to have it ready by summer!!
Sounds like its gonna be a sweet build! Is there a lot of fabrication involved in putting the tranny in your a body?? How are you going about doing that?