??W2 Econo valves??

SSG_Karg said
How can that be? Wouldn't two different length valves require different rocker arms?

Yes if you do not raise the height of the bar that the rocker arms ride on.
That should be the answer to the above mention on how to get around things.

If I run standard length valves, I assume I can run the standard offset rockers for the Econo head.

Yes There designed with use of standard 340 T/A rockers in mind.

But, if I use the long valves and taller springs, can I still use the same rockers?

I do believe so. This I do not know for sure, but *I think* the answer is yes.

I guess I would run the standard length valves due to them being more commonly produced if they both work on my heads

That is what I would do unless your cam is extra big on lift.

I've seen other posts here saying things like "It depends on what size the rocker hold down bolt is". I just don't want to end up buying the wrong length valves.

Your not running a giant cam lift are you?
If your not, stick with the standard length valve.