I need advice for a good street performance/economy slant 6

Remove the complete exhaust system and go with 2 1/4 inch pipe to your manifold with a good quit 273/318 muffler for some back pressure and defiantly get rid of the point system.
When you do the plugs use the NGK plugs and remove the washer if you have drool tube heads, this made a giant step forward for me krazykuda. It's all in my restoration thread.
I got allot of help from our members here.