Rocker arm ratio?

[hillbillybowtie]

Im trying to get a understanding as to how the different ratio of the rocker arms affect the performance of the engine. This might be a stupid question, but im trying to figure out what the adventages and dis advantages are. I keep seeing the 1.5, 1.6 and 1.7 ratios on summitracing but dont understand how they work. Any explanation?

[Atomic]

higher ratio will give you more lift since the rocker multiples the valve movement. Also increased opening and closing rates since it has to move a greater distance in the same time (using a higher ratio rocker).

[daved931]

Higher ratio will give you more lift. Keep in mind that if you switch to a higher ratio, you may need to clearance your heads for more pushrod travel and upgrade your valve springs.

[hillbillybowtie]

OOOOOOOO, ok. so it all depends on the cam choise too. I gotta go to my machine shop this week to bring him my pistons for my 383, mabey ill ask about my heads too while im down there to see if i am going to need a different ratio with the new cam. Thanks guys.