Upgrading A 250 L-6

[snowman4839]

Hey guys. I'm 15 and I just got my first car. Its a 69 Buick Special Deluxe with a Chevy 250 straight six. I was thinking about putting a 4-barrel, headers with dual exhaust, and if I need to (which I probably will) get a heftier cam. I was also thinking, if I have some extra time and money this summer, getting a 292 crank and rods and putting that in for more displacement and higher compression (would this need premium fuel?). Any ideas and or tips?

4 barrel intake - http://www.summitracing.com/parts/OFY-5416/
and for a carb, I have an old quadrajet off of a GS 350 but I need a $100 adapter plate and get on the fast track to learning how to rebuild it. It is also probably a 600cfm. Would that much cfm be too much for such a small disp.? Or I could get a smaller 4 barrel holley that would most likly be a 400-500cfm that would bolt right on and I wouldn't have to spend the extra $100 for the quadrajet adapter plate.

headers - http://www.summitracing.com/parts/BIG-11510FLT/
and I would get some 2.5" and weld it up with two of these mufflers

and one of the High energy series cams if I need it

Looking for ideas, tips, and feedback. I know it's a buick but the guys on the buick forums weren't helpful with a chevy engine.

-Thanks