1 Professionally built PVC-CAI going cheap!

[Aussie Mike]

Easy Peasey, Get some 2" mandrel bends in the angles needed to run up and over your throttle bodies just like if you were doing 4 of them as originally planned. Once you have made 1 run up split the pipe lengthwise into 2 equal halves. Now from some sheet cut 2 strips the width you want the oval to be and bend them to follow the contour of your 2" pipe. Weld the halves of the 2" pipe to the edges of the sheet to make a flat tube.

With your 3" outlet pipes, get a piece of 2" or smaller steel bar and clamp it in your vice. Use this as a stake to oval and flare the ends of the 3" pipes into a 2" wide oval flare. You will be amazed at what you can achieve with some judicious use of a hammer and a variety of stakes and punches. Shape the pipes to form a collector on the end of your wide oval pipe section and weld them in place. Rather than make the whole intake in one piece, I would join sections of the whole thing using short pieces of rubber hose. This will make it mush easier to work on and it'll give you a bit more tolerance for your fabricated bits.

I guess it's a bit confusing in print so I'll draw a picture of what I'm thinking if you like.

Cheers