i am in the process of scrounging up parts to build a 468. in the mid rpm range like occasional 5500 or would i be better off with close chamber heads for that type of rpm . thanks

Both of the head casting numbers you listed are open chamber, usually around 119cc's. What closed chamber heads do you have in mind?

With the rpm range you're considering you won't need much cam so major compression won't be needed. Shave the heads some maybe and get your deck height set right. From what I hear the 049 and 781 heads flow the same. You should add larger valves 2.19/1.88 IMO.

I have seen fast street cars built with both the closed and open chamber style heads. Either one will easily support 5500 rpm (with a decent cam, intake and exhaust system). Make sure you get the bigger oval style heads and not the peanut ports. I ran mid 11s with 3900 lb street chevelle with the 781s shifting at 6500rpm. I was very pleased with them. They had 2.19/1.88 valves and a mild bowl work. But unported, stock 2.06/1.72 valves sized head should pull 5500 rpm.

049's and 781's are the same head more or less..both excellent open chamber heads.
Either one you can't lose,stock or done up.