Camshaft + converter for 318 w/302 heads

Well, if you "bracket race it only", then the next question is "are you looking to go fast?"

1. yes, the .474/280 cam will work. I've used that cam in a few 318's (street cars)
2. I would run a quality 9.5 converter, on the loose side (3800 stall)
3. I would gear it so that you cross the line 200 rpm's before your shift point. That won't be 3.55's. It will be around 4.30's - 4.56's
4. I would sell both your intakes, and buy a RPM air gap (edelbrock)
5. Yes, you can port the 302 heads. I'd advise it or they will be the bottle neck of your combo.

What E.T. are you hoping to run? What class?