Just so you know. A stock corvette lid has a 4 inch coupler that allows you to run 4 inch hose/tubing straight to your TB instead of necking down to 3.5.

I realized this when i was cleaning out my shed, and im going to use it on my setup.

 

Gotta picture so we know what you are talking about? I just used 4" aluminum pipe and some 4" -> 4" silicone couplers.

 

when a lot of guys run SD they just make a 3.5 inch pipe to replace the maf. so the airlid necks down to 3.5 then the bellows expands it up to 4 inch for the TB.

A stock corvette lid has a 4 inch opening, so that you can take a 4 inch hose straight to the TB.

None of this really applies to me because i am running a MAF and a q45 TB, but i figured someone would be interested in knowing.