Sorry, not enough info. What do you intend to do with this car? Daily driver, drive-in cruiser, dragstrip. Why do you want the tunnel ram? Looks? What 327 are you starting with? Original HP? What heads, cam, etc?

An engine is a system, not just a collection of parts. The carb, intake manifold, cam, heads (including compression ratio, valve size and runner size) pistons and exhaust all have to match up. Otherwise, any one of the combination will choke off all the others. All of these components have an RPM range where they work best. Mix them up, and you've got an expensive boat anchor.

What you do to the motor depends on what you want to do with the car. If you want solid power and driveability on the street, that's one thing. If you want a screamer that only works when you wind it up to 7 grand, that's another.

Tunnel rams are a pain on the street. It can be done, but they don't work very well at low rpms. They work best above 3500 RPMs. If you try to run one on the street, you better become a carb tuning wizard. Do a search on this site for "tunnel ram" and you'll find a bunch of info.

There are many ways to build a stout 327 that works well on the street. Chevy got 375 HP out of them a few years ago.

Think about what you REALLY want, then ask a couple more questions.