1) INSULATION. The 1968 and 1969 Corvettes had very good underbody insulation. The factory insulation covered the lower half of the firewall (on the engine side of the firewall), completely covered the inside of the transmission tunnel and also under the floorpans. The floorpan insulation was on the outside of the body and steel sheets were added to protect this insulation form road debris. The underfloorpan insulation was dropped beginning in 1970. The insulation pads for 1968/69 and the steel protective sheets are still available (Paragon, Volunteer Vettes, etc). When I had the engine/tranny out of my 68, I redid all this insualation. On the factory assembly line, the insulation was only put in place...there were gaps between the various insulation pads, transmission liner,etc. When I redid my insulation I used extra pieces cut to fit some openings and sealed every thing with aluminum tape.
On my 70, with the interior and dash removed I added extensive insulation inside the car passenger compartment. Once again I used aluminum tape to carefully avoid any openings. I've also bought all 68/69 insulation hardware and will install that eventually on the 70. So my 70 will end up with the 68/69 factory insulation system.
2)EXHAUST When I first started driving the 68, my right foot would almost literally be roasted by engine heat. I would imagine the exhaust pipes running along side the tranny will get somewhere close to the upper hundreds of degrees. Except for the fiberglass body (0.150 inches?) and maybe 3/8 inch of fiberglass insulation (if it's still there in an older car), your foot is probably 6 inches away from this heat source. SOLUTION - Not everyone's cup of tea, but sidepipes. I installed the factory 69 sidepipe exhaust system and the heat problem when away. In the early 1970's the factory sidepipes were not that expensive, but today you're probably looking at $2500. Plus they are noisy.
ush:
