I have a 77 with a 305 it has a mild cam with stock heads (with the exception of 1.6 roller rockers) a performer manifold and a holley 600. It also has headers, flowmasters a 2800 stall and 3.73 gears in the rear. I want to go with a big cam (around .500 lift)and a new set of heads. What would be the best combination to go with to get the most power from the motor.

You can probrably get a decent cam under .480 lift and use vortec heads for cheap as is without modifying springs or machine work

Be careful with selecting too large a cam for a 305, you could turn it into a dog below 4500 RPM. Doing some portwork to your heads (or better yet, get some 601 casting 305 heads and port them) and limit yourself to a cam in the 210 to 218 degree @ .050 and you should have a sweet little performer.

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