big block options ??

One thing to consider before making a decision is what headers you want to run. Some of the popular headers were designed with the RB in mind and won't fit quite as well with a B motor. Also there are more intake chices for the RB. Holley doesn't make the Street Dominator for a B anymore. Weiand doesn't make a tunnel ram for one anymore either. Don't make your choice in large part on weight savings, as there is not that much difference in weight between a B and RB. The B is more compact of course. Some good info her: http://www.arengineering.com/articles/sonicbig.html