Goblet is absolutely correct. But if you are indeed set on buying a manifold then tbss would be best option

 

Just my opinion. I was looking at all the same crap fast-ls6-edlebrock-tbss. The cheapest route tbss. The most expensive fast. They all can be modded but I decided to go Holley Hi-ram 102. Why cause it comes with the fuel rails unlike all the others so its a few bucks cheaper in the end. Plus it can be opened up and modded. Has the best of both worlds for hp and tq. And If I go from cathedral to square I just get a new lower. Lots of advantages to the Holley Hiram

 

I defanitly felt a difference throughout the power band switching to my TBSS intake

 

I'm running a Pro-Flow XT and like it! No difference on bottom end, however above 3500rpm's are GREAT!!!

 

you didnt mention the fast lsxrt 102mm?