How much difference will it make?

I'm a parts vampire .
Building a track car .

I hate to put it that way. Maybe buzzard or vulture would be better. But whenever I see parts that I'm interested in that somebody may want to part ways with, I have to speak up. They don't make a lot of these parts anymore. Some of them they haven't made in a long, long time. And I'm finding they are difficult to locate. Like W2 mechanical rockers .
I'll be circling in the sky above .