Hello PekingtoParis,
You are in for one Helluva' ride! Congratulations on getting into the 2013 P2P.
Did the Rally Association send you Philip Young's book "How to Build a Successful Rally Car"? It has loads of good information.
I would be careful about making too many changes or "improvements" to your car. It seems that on the 2007 P2P, many of the suspension problems were caused by folks trying to add to or change an already well designed (ie original) suspension system. Like Chevgene said, if its the front shocks, the lever action was part of the suspension system. If the shocks work, I'd leave well enough alone. We drove a '30 coupe in the 2007 P2P and the only changes made to the suspension was the replacement of the standard passenger car leaf springs with ones made for the 1/2 ton pick-up truck. We left the original lever action shocks in place and they worked fine. Looking at some video taken as we were crossing the desert, the springs travelled to their full limit, both in compression and expansion. So expect some rough roads (where there are roads). Our car was left as original as possible, and I think one reason we didn't have suspension problems was because we didn't try crossing the desert at 60 mph (like some of the Bentleys).
Anyway, you are in the right place, here at Chevy Chatter, to find information about your car. This site was an enormous help when I was prepping mine for the 2007 run.
Good luck and have fun,
Dan
Car 34
2007 Peking to Paris Motor Challenge
