Todd - Yep, ever had a wastegate fail on the turbo of an '85 Volvo 760?
#2 daughter (probably drag racing) simply told me her Volvo was making a
"funny" noise.  $1200 later, the "funny" noise ceased.  Right now, I'm
using the valve assembly from my old OHIO anesthesia machine to meter
N2O into the throttle body.  It's a LONG trip back to the throttle body,
but I haven't figured out just what remotely controlled valve is
available that would allow flexible metering of the N2O at the throttle
body, reliably.

Really don't know what all this "head gasket" business is about.  The ex
"cooked" two engines and one tranny between the time "Bourgeois" became
a member of the family in '91 and our divorce in '94.  I'll meet that
challenge head-on if it occurs.  Besides, the N2O I get from my oxygen
supplier doesn't have that funky sulphur additive the drag-racing
nitrous has in it, so, if I blow the engine in me Vanagon, I'll just
"inhale" for a while and "be happy"!

BOB - '85GL