The header adapter pipe design went back to the drawing board. My first design had two flaws. First flaw was that the driver side pipe touched the fiberglass floorboard. Probably answers the question “Why is that Corvette on fire?†Second flaw was the proximity to the transmission. My original simple pie cuts brought the pipes on both sides so close to the transmission that I’d need two extra trans coolers to compensate.
My solution is to abandon the stainless plumbing and use plain steel. Ordered a pair of 3-inch to 2.5-inch reducer and flange, two 2.5-inch mandrel u-bends and an oxygen sensor bung and plug. I cut and tacked five pieces of pipe for the driver side and three pieces for the passenger side. Bends are all pretty smooth and the oxygen bung faces the transmission.
Once I finish plugging the pinholes in my welding, I’ll send the pipes to Jet-Hot to be coated inside and out with the same coating as the headers. That gives me the benefit of rust-resistance comparable to the stainless and adds the benefit of reduced heat around the floorboard and transmission area. I may attach some heat barrier material under aluminum flashing to the floorboards next to the headers if there is still a heat problem.
