I have a set of World Sportman II iron heads that need new springs.I need to know what size to get for a stock cam with roller lifters and 1.6 roller rockers and also what length push rods. I appreciate any help thanks.

You probably dont need crazy springs at all. Just get something good to .550 lift and call it a day.

To stay cost-effective it's probably a good idea to get springs that are the same diameter as your existing retainers so you don't have to buy a new set. For (stock size) 1.25" retainers a set of Comp 981s will do fine with that combo of parts. For larger 1.45" retainers a set of Comp 986s would work fine, with 987s being acceptable as well, if a bit of overkill for a stock roller cam. If they're the big-boy 1.55" retainers you won't find what you need and you'll have to get a smaller set of retainers to work with appropriate springs.

What's the maximum RPM and how much lift at the valve will your 1.6 rocker arms get you?

As for pushrods, who knows, you'll need to measure that.