Marty, I've had fuel vaporization problems twice since I've owned my car. The first Fuel vap. problem was due to a leaking exhaust manifold. While learning how to maintain my car, I ran the carbs overly rich for an extended period and warped my exhaust manifold and ended up shearing off the manifold studs at both ends. Prior to fixing the actual problem, I ended up installing a later Z hood with louvers. This had two benefits: underhood temperatures where reduced and the front end lift at high speed was also reduced (evidenced by the fact that the rear corners of the hood no longer lifted at high speed). To further alleviate the fuel vapourization problem I re-wrapped the fuel rail with insulation and covered with aluminum tape. More recently, I installed a MSA 6-into-1 header (coated) and ended up having a fuel vap. problem again (especially if I went through a drive-thru). The problem was that one of the header tubes passed directly underneath the rear carb float bowl. After a few minutes at idle, the float bowl would get very hot and fuel vap. symptoms would occur. To rectify the problem, I got some scrap metal and manufactured an extension to the stock heat shield which extended under the rear carb bowl. I covered the under side of the new heat shield with insulation and aluminum tape and have since had no problems. This solution is not the most aesthetically pleasing as the view of my coated header is obscured but it works. Cheers,