Pushrod Problems?

Hello
We are working on a 79 225.
We are putting a Comp Cam in it when it goes together.
When we mocked things together the adjusters for the rockers won't reach the pushrods with the nuts on the adjusters.
We noticed the same was true before doing anything.
I guess I'm trying to find out if there are different length stock pushrods?
Is there another reason for this?
Thanks