[xj-s] XJ-S engine heat

Local auto parts distributors are advertising two products which are
claimed to significantly reduce engine operating temperatures and under
hood (bonnet) heat. One is a radiator additive for engine heat reduction,
the second is an exhaust header wrap material to reduce under hood heat. It
is claimed that this material resists heat of up to 2,000 degrees F. Anyone
have any experience with such products?

Jim Brown
85 XJ-S