New to the A body scene, school me!

Torkmnstr said
I am thinking more along the lines of a pro touring feel. I want her to run like she's on rails, have you guys heard anything good about the hotchkis tvs system? As for motor I would eventually want to move up to a 340. As for now and funds allow probably bolt on stuff like manifold, mad excetra.

Below is the way I'd go. Skip the 340 and still make the same HP at a lower rpm with more torque to boot. Though I don't think I'd stick with the 273 over the long run.
The roller 360/904 combo is an excellent one. 400HP from a roller 360 is easy and very streetable. An 8-1/4 rear is more than capable of handling this power level. It will also save you a lot over a 8-3/4.

I do not know what Hotch has for your car but the do make very good stuff.

1970Duster said
Do your suspension setup first. Then acquire the motor you want to use, take a real hard look at the late 80s/early 90s LA 360 Roller Block, pretty much the top dog of production LA blocks. That roller cam setup is a big advantage over standard flat tappet blocks.
Personally I'd just keep the 273 running (maybe swap on a 4 bbl intake and carb and that's it) because you want to swap out to a bigger motor later anyway. More money to build the bigger motor is always a plus.