absolutbspec

Can anyone give me a link or something that can help me understand lift, duration etc....also how it relates to the heads?

Anything helps. so i know what im looking at when i go to buy heads and what im talking about when i order a cam.

Bold_Yellow

Well the higher the lift the farther out the vavles go and duration is how long the valves are open for (more duration = more time the valves are open)

Just basically pick a cam with in the same rpm range as the heads, I find 112 and up lobe center makes more power on these sbf's.

Hope that helps somewhat.

absolutbspec

but what about pushrod length.
Also say i get 1.7 roller rockers how does that affect lift etc

Hung Like a Stang

push rod lengths depend on heads (I.E. tfs heads), as well as other clearances.

from a pontiac street performance article by Jim Hand (yeah yeah, he's a poncho guy, but good nonetheless)

Summary:

Higher ratio rocker arms open the valve faster, higher, and hold it open for a much greater total period of time as compared to lower ratio units. Does this cause more stress on the valve train? There will be more pressure on the cam lobes due to the friction and pressure caused by the higher lift and resultant greater spring load. However, as compared to providing the same higher lift and effective longer duration with a more radical cam and even stiffer springs, the higher ratio rockers may create less total valve train stress. And such a cam lobe would be very aggressive and would require much heavier springs to keep the lifter from flying off the lobe. Very radical lobes will also add more side stress on the lifters/bores and could possibly cause lifter bore failure. The added pressure on the studs from either higher ratio rockers, or more radical lobe, will be well within the capabilities of modern after market studs.

here's the full article

http://www.pontiacstreetperformance....ockerArms.html