Some of the common ratings on the 283 were 180hp, 195 hp, & the mid 60s powerpack (car) was rated @ 225 hp with dual exhaust & a 4 barrel carb. I would stay small tube (1 1/2") on the headers, & a small 4 brl like a 500 cfm edelbrock. cam selection is critical on the smaller cube engines, you may stick with a stock cam listed for a 300 hp 350 (also used on several others), or a Crane Energizer 260. Exhaust pipe size should be no larger than 2" for a dual system on the 283, & i would add an H pipe to the system. This would make a good driver /cruiser, & will have enuogh power for hauling. I have played with the "hotrod" 283s with big cams, carbs & such......but they are better suited to a lite car with a 4spd & low gears. Good luck......crazy AL
