Balancing and Pistons ?

Here is what is going on, last race a valve broke. I messed up one piston real bad and have to replace it. I have another complete set of same pn #. I was planning on using one in place of the broken piston. The problem is the replacement pistons are 66grams lighter each. Should I just get another new one or replace them all ? I don't have time to rebalance before the race.

Thanks Guys !
Jim

Take the time to get it rebalanced, Odds are with TRW type stuff your going to get a different weight one even with new ones.

Certainly don't use ONE piston which is 66 grams lighter. Buy a set of heavy wall wrist pins which weigh 40 or so grams more and use that whole set of pistons.

EDIT: Re-balance it with the lighter set of pins the next time you have it apart.