I've been reading around and havent really found if this is okay. Some of the rockers are able to be picked up some when the pushrod's are at the lowest point. Its not loose, but they do lift up some with the pull of your hand. The ones off the other motor dont budge. I found rocker shims in the box they came in, but im not sure if I should put those in or if this is how the rockers should be when the motor hasnt been run yet. Would it be okay to run the motor and let the lifters get primed with oil in them and then check the rockers again? or do these need shimmed?

 

Most of the time the shims are not needed if the heads are stock, you should be ok , start it up & see , the lifters will pump up ... Lew

 

The heads are all stock. the only thing I have done was put new seals in and a resurface. Hope everything goes okay. Thanks lew

 

what type of performance difference are we talking between the 1.6 and 1.7 rockers using a cam similar to the mustang as a baseline comparison.

 

I was told that just going from 1.6 to 1.7 will give a slight advantage. More lift for the cam, little more air flow. The comparasion was like advancing your timing from 10* to 14*. Not a hugh gain in performance, but it is noticable.

 

I agree its a noticable good mod ...

 

but if you go to buy a cam it will be harder since you have to factor in 10% more lift than factory 1.6 ratio

 

so if you go with the 1.7 then you'll probably want to do a custom grind for the cam?

Would it make any difference if you were using gt40p's. with a stock cam and 1.7. I know the torque and comp ratio for the heads are different. Just wondering how the 1.7 rockers would play into that. It seems they would cut down on low end torq a bit.

Also, anyone have experience with high-end vs mid-grade valve springs and notice any difference between the two, or is it that the high-end springs are for heavily mod'd blocks?

 

those springs are for higher lift cam to stop Valve Float.

 

the rockers shouldn't cut down on torque since they don't have anything to do with duration just lift and your powerband is more determined on what your duration is than what lift you are at, you want your lift to be around where your heads flow the best