rover boost pin springs

[wisconsinjohnson]

I am wondering if anyone knows the difference between the available rover pump boost pin springs.  I am not sure what pump my boost pin is from, but its pn 1463 123 413-770.  When I purchased it, I asked for all available springs, and there were three,

 1 464 617 712,
 1 464 617 713,
 1 464 617 715
 
I put the boost pin in my aaz pump right away, but when I saw how short the springs were, I assumed they were for a starwheel pump, oops! The two I've tried recently have been a vast improvement, and I have what I think is the stiffest spring in now, 715.  It seems a little shorter though, just wondering if anyone knows what applications the different springs are for.  Also wondering if I should be shimming the spring up/what would be the best way to do that. I'm trying to reduce low boost enrichment, but I've all ready lost so much power to altitude, 10,000' that I don't really want to back off the smoke screw.

thanks