You mentioned the header tube is near the booster but is the booster actually getting excessively hot because of the header tube location?

It's going to be hard to get a smaller aftermarket booster that will work as well as the OEM booster.

Header wrap isn't exactly the most attractive looking but it is effective at controlling heat from the headers, as well as reducing underhood temperatures.

http://www.jegs.com/c/Exhaust-Headers-Mufflers_Heat-Shields-Insulation-Header-Wrap/10261/10002/-1

Ultrastang- I haven't ran the car yet with the current setup however my mechanic is concerned the heat will damage the booster, will exhaust wrap help that much? The tube is approx 1/2" from the booster.

Mustang Steve- I had to purchase specific headers to fit my application ('69 convertible, manual tranny,power brakes) and at the time (few years back) there were only a few choices of headers that'd work. I believe I went with the Hooker Super Competition Headers 6208HKR. My mechanic has suggested possibly installing a heat shield but I'm not sure I'm fond of that idea because of how it may look......insulating will work well enough even with the minimal distance from the booster?

Thanks for that info MS. Eased my concerns.