This is for talking about how to change TB'* to a larger size. There are a few different sizes available on the bonnie alone, but i'm gonna do one from the grand prix book personally. Ls1 TB'* have been run on many 3800'* just fine, but they're backwards. Northstar TB'* are the same size as LS1'* (75mm) but are setup for fwd applications.

My big question is which MAF do i use? I'll most likely be getting a Mini AFC, but would the N* one be best since it'* calibrated for the diameter?

You know I've thought of this myself, just where do you go and what size is needed?
At what point does it become apparent that the TB is too small and you need to step up?
I guess with the fuel ratio being to lean and looking beyond the afc? Not sure?

The MAF is in tune with the pcm, so I guess the maf must be within the pcm frequencies and scaled to the TB diameter?

What about this one from Intense?
http://www.intense-racing.com/Merchant2/merchant.mvc?

Its for a L36, but can you modify it to fit your rebuilt?

looks like the LS1'* are only for SCed engines, I would go for a ported one instead. It would probably be cheaper too.

how much of a difference would you actually see by switching the throttle body out?

I'm going from under 70 MM to 75. The response is one of the biggest benefits of it.

Possibly a good 10 hp, maybe?

Well I dynoed my Aurora with stock TB, than RSM CAI, and then RSM ported TB to 80mm. The gain was around 8hp @ wheels gain at the peak, The advantage to a bigger TB is power added accross the WHOLE power band.

Here'* a nice write up my old Aurora buddy did. http://caddyinfo.netgetgoing.com/reviews/tb.htm

I my self am still deciding with what TB to go with, The LS1 looks nice but big bucks, considering just getting the stage 2 HVTB, stock ported, my dealership probably won't even know when I go in for work, not the story with a big ls1 with a monting plate, looks far from stock.

3800 performance is coming out with a N* conversion kit Taylor. It'll look stock, since it'* setup for FWD.

While kinda, the Northstar TB is shaped different that our 3800'* TB. The tech will notice right away I'm sure. I think I might even have a Northstar TB in my closet somewhere, I never returned for my core charge.