Overheating on the highway. 76, 2.0 Options

[SVG223]

My 914 overheats on the highway. I had concerns about the air flap, but I think the thermostat has broken and it stays in the open position. I thought something might be clogging the fan but it looks clear. I wonder about the heater air hose that goes over the motor. It could be blocking some air possibly. I may try to tie it out of the way. After exiting the highway and stopping at a stopsign the idle was extremely low, I was surprised it was still running. I turned the engine off for a while and it ran better after it cooled down. Any ideas would be appreciated.

[wonkipop]

@SVG223

hey thats a good looking car you got hold of.
i looked at the photo gallery in the link you posted.
seems to be all there, very original and in nice condition.

without wishing to add to lists of what could be wrong -
@emerygt350 suggestion of a blocked cat isn't silly and worth checking.
i can believe that car just might be a 50+K miler and if so might still have a 45 year old cat on the exhaust. i couldn't see if so from the dealer ad photo gallery.

good luck with it and follow the D jet guys advice on this forum.
i own an L jet so wouldn't have a clue when it comes to these.

but don't forget to keep the revs at 2800-3000 out on the highway for aircooled peace of mind.

EDIT - ps checking out that photo gallery your heater hose looks fine and shouldn't be blocking fan air flow. its all beautifully stock in there and in amazing condition. and i got into the full gallery at high res - its still got a cat on the exhaust. (IMG:style_emoticons/default/blink.gif)
it kind of looks original.