As most on here seemed to say Lokar for throttle cable, I checked their website for part numbers,then managed to find TC-1000TP36 for $66.88 shipped. I hope that's the right one!

Then I found BBK-1583 for $14.99 shipped on ebay.

Any install advice on Lokar cable is appreciated! I'm finally going to try to sort this 87 IROC out...

 

https://www.rockauto.com/en/catalog/pontiac,1987,firebird,5.7l+350cid+v8,1251414,transmission-automatic,detent+cable,8484

$16,90

 

I think that is the throttle valve cable for automatic transmissions, but it does beg the question why a cable much longer costs much less haha

 

There is a big problem with part numbers for the correct throttle cables. The ones from Auto Zone, etc are too short. I don't know about Lokar.