1676 eldorado speedometer cable issues - again

[76 cadillac bob]

My last post on this matter was June of 2018. Yesterday in the heat of the day, I had to drive the caddy and the black sheathing melted as it was too close to the exhaust manifold. It snagged the innards and  twisted the cable into a pretzel.
My engine was very hot boiling over a bit think timing is off....I do have a new radiator. Anyway, this happened two years ago. I have bypassed the cruise control and now go directly from the speedometer to the bell housing next to the transmission. Is there a good metal sheathed cable I can purchase and not have to have a melt down one more time? Luckily no damage to the mechanism next to the transmission as far as I can tell it all works as it should.
Thanks
Cadillac Bob

[The Tassie Devil(le)]

The only way to get a metal sheathed cable would be to find an original 30's or '40's GM cable and retro-fit the ends.

I do know that a speedo cable for a 1937 Chev will fit a 1967 Chev, and every year in between.   Some things never need changing, but the later ones had the plastic/nylon outers.

Bruce.

[TJ Hopland]

Do you maybe have some sort of exhaust restriction causing a lot of extra heat?   Cat converter?  Even if you know its not the cat how old is the muffler?   Cadillac type mufflers typically have an internal packing that is a soft insulation like material.  You could have internal corrosion that let the packing out of where its supposed to be and its now restricting the flow.     Also decent chance some critter could have lived in there sometime over the last almost 40 years. 

[76 cadillac bob]

I suspect the cat converter, it is very hot, going to cut it out. I replaced the exhaust 4 years ago, from manifold to tail pipe. I wonder if a critter did get in as I had mice two years ago in the car waiting to transport from San Diego to Boise. It should not be getting this hot.
Meanwhile ordering another cable, I am just going directly from speedometer to tansmission no cruise control.