if i go with adjustable rockers, does it really matter if i use 7.40 or 7.35 pr's?

 

Yes it matters, since on non pedestal rockers they perform a dual function:
1- They affect geometry on valve
2- They also affect lifter preload

On our stock system they have more of a preload effect than geometry effect since the rocker system is non adjustable.

 

so what would i be looking at to make them work? just a normal pr length check? is it just a better idea not to use them for a mostly street driven car?

 

There are a lot of advantages to using them, but some (like Crane for example) use a different arc arrangement and sit lower at the pushrod end therefore you need different pushrods. Best to measure, but once you do you have the advantage of being able to set your lifter preload.

 

i ended up getting the comp type r lifters and the adjustables are what they say to use. looking to get a set of hs adj. rockers.