Tell me about roller rockers
 

I just picked up some GT-40 heads on e-bay that I am planning on getting ported a bit and Iam getting some other parts together. I have heard about the rockers before could you fill me in on what they do if they are worth the money and what ratio would be best for me. Thanks for the help.

Chip

Pedestal mount crane 1.7's will work out, you just have to be careful running 1.7's with a big cam, you shouldnt have a problem.

Fill me in too. For some odd reason a friend of mine swears that all 5.0 HO has roller rockers. When I changed my valve cover gaskets today I noticed that I do not have roller rockers. So we have that established. What's the difference between the HO and non HO 5.0? Cam? Thanks. Rob

Your friend is referring to 5.0HO's to having roller cam's. The only mustangs to come stock with roller rockers are the 5.0 cobra's.
The roller cam uses roller lifters that basically have a wheel on the bottom of them that "rolls" over the cam. The non HO motor has a normal flat tappet cam

Roller rockers have a cylindrical bearing that the rocker pivots on and thus causes much less friction than a non-roller rocker.

The ratio (1.6:1, 1.72:1, and so on) has to do with how much the rocker will push the valve open compared to how much the pushrod is lifting the other end of the rocker.
With a 1.6:1 rocker arm, if you had a cam that pushed a pushrod up 1 inch, the rocker would then push the valve down 1.6".
I'm just using these numbers to clarify things, not that you would ever find a 1.6" lift cam.

Anyway, if you plan on installing a cam in the future, then I would reccomend the 1.6 roller rocker arms. This will give you a better choice of cams to choose from without having to figure out the lift that you'd get with 1.7 rockers. (the lift on cam specs are with 1.6rockers).