Thought I would post this here for you Qjet fans. I posted this on LS1tech as well, but it's more appropriate here I think.
Couple years ago, I decided to jump on the LS bandwagon for one of my cars, a 1968 Camaro. I went with the L33 all aluminum 5.3, mild cam, headers, and, of course, fed by a Quadrajet. The problem is there are no LS intakes on the market that enable us to install a spread bore carb, other than using an adapter/spacer which I didn't want to use because of the intake volume it added and the "funnel" effect.
So I bought an Edelbrock Performer RPM LS1, had the secondary side of the intake enlarged by having two aluminum plates welded, one on each side, and had a machine shop bore the intake to match a Qjet baseplate I gave them. Here is the result.