I lost some power when I got new tires 35,12.50,15 Mickey Thompson rare tires
Any way lost power , that ping noise that he's talking about could also be distrib timing
When chains stretch they get out of wack , mess w the distrib then drive then again , timing light might help, but that ping noise should go away , when you adjust it ,,,

But.     I bought a 32 36 weber from a junk yard and messed w my timing and I still drop back to third gear , sometimes second gear , but your power will Scream
79 cyote will help you if you end up getting a weber

Long story short. We ber has 2 bigger barrels and the air fuel choke idel are soooooo easy to set up  this should get your power back !! Good luck hope this helps.