66 273 Cam and Intake Thoughts

I'm with Terry. An aftermarket intake to look at would be the Edelbrock Performer. It has the small runners for the 273/318. So in that, the match will be good. That intake is also equiped to use the T-Q. So you'll save on getting a new carb there.

On the exhaust, the tube size is HP dependent. 2-1/4 for your engine (IMO) for about 1 hp per cube. If you plan to exceed that, 2-1/2 is fine. Large, but fine for the top end.

A cam is a little tuff to call with the surplied info. Tell us here the;
1. rear gear ratio. There should be a tag on the rear end cover with some numbers. Otherwise, the 1 of the other 2 ways to know is to do what probably hasn't been done to the car since new. Change your rear gear fulid and look at the ring gear for the ratio stamped on it. I'm not a fan of the other, pick up the rear and spin the tire and count the tire vs driveshaft revolutions for a approx. guess.

2. tire size. (Or what you intend to run)
3. are you gonna change the stall converter? and is it stock?
4. the cars weight. (The reggie has the cars close enuff approx. weight.)

Answer these questions and we'll be able to better zero in on a cam that will be better suited for your intentions.