I was taking a TIG course at the local junior college, FCCJ, and did a "stretch" intercooler as a project to help me learn to weld aluminum. It's now on John Larkin's car; he's run low 12s with moderate boost on a stock motor with it.

It would take me a page or two to describe the project; it was a pain. I'll synopsize here. I cut one core in half between rows. I then cut the end tanks off of both cores, leaving the necks on the full core. I cut the inlet of the IC off with some room to spare to attach a 2.5" cast elbow (similar to the "Duttweiler neck" mod but using a generic Turbonetics cast elbow). The bracket on the bottom of the full core had to be removed as well.

I welded the half core's header (the area between the fins) to the bottom of the upper core. Next I fabricated new end tanks from sheet aluminum and bent them to shape with a brake and welded them on.

Finally, I used a plywood jig that I'd made from an uncut IC to locate and weld on the new inlet neck and the side mounting bosses.

Whew! It was a good class project but I'd go broke trying to make these for a profit.