I mocked up the exhaust in hopes of finding out what parts were missing and I can't locate the little flapper doors and the pins they hang from. I assume they are to prevent the air from flowwing the wrong way. Are they bimportant? Also I see there are gaskets on the flange between the shroud (same place as the flappers) and the "S" pipe that connects ti the HEs. The gasket is something like $60! On my other car I don't recall a gasket at all. Are these important?

Yeah - it's also part of the air cooling, cuz the flapper sends the hot air pushed through the HEs either into the cabin or ejects it our the "Hat" top as hot air into the airstream under the car (or a combination of both depending on the flapper setting). If they're not there or the line is capped off, then it won't flow out the hat as well due to internal turbulence apparently, plus no cabin heat.

Those who cap off at both J-tubes or the ends of the HEs are just asking for more heat to build up around the engine, plus back pressure on the impeller fan.

IIRC part of the reason that the 75-76 914s went to the 2 sided heater hoses was to help cool the hotter running 1.8 & 2.0 with the added EGR, Crap-a-lytic converter & other smog control stuff which made them run a bit hotter. May just be a 914 urban legend, but I think that was the case anyway!

The gaskets are nice but I ran without them and with ee, not a big difference if noticed at all.. you can get flapper door repros and originals here.. pins you can make out of cut in 1/2 cotter pins..

http://www.germansupply.com/home/customer/...p?substring=914