The question I have is will you really gain or even us the extra 5mm (75 vs 80mm) Tbody until you reach somewhere around 450 rwhp? I don't want to **** away $300 on 2-5rwhp gain on that. Now I may be totaly wrong so correct me if I am.. I have as you see below in my sigs what i've done so far, my next goal is a cam, and after reading some post on the Ls6 cam that may be the way that i'll go do to warrenty issues. Now I'm running rich as it is and going to get dyno this Sat 31st. and try to use my MAFT to help out somewhat. Until I do a cam swap then I'll have someone reprogram my PCM but I just wanted some feed back thanks.. Also wouldn't the Tbody lean you out some?

 

Don't waste your money on a new throttle body. The only good ones are the ported and polished factory ones. The one you are using now is good to more hp than 450. I've got a blown app. and I am running more than 540 hp and 500 tq without any problems.