The KB are lighter. the TRW sixpacks contrary to what he told you ae the same weight as stock. That is why they are called Replacement pistons and not race pistons. They were designed to be used in a stock rebuild with out rebalance. but were the premuim choice. If you like I will send you the warning in the KB book about tight ring end gaps. or you can search Kb pistons on the internet and they hae it plasteered all over. We see it all thetime here. Gaps at .012 to .014. Engine runs for a eek at best. When we talk to he Engine builder and ask dID YOU READ THE INSTructions we get a blank stare. Author of so make sure he is unwaverlingly on side with no reservations. Don Return to Deutschland (True Adventure) Old Reliable (Mopar) http://altonapublicschool.faithweb.com/ http://seniordragster.bravehost.com/index.html [Non-text portions of this message have been removed] ---- Please address private mail -- mail of interest to only one person -- directly to that person. I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic. Thanks! '62 to '65 Mopar Clubhouse Discussion Guidelines: http://www.1962to1965mopar.ornocar.org/mletiq.html.