Here is the deal with my 67 coupe. I've been experiencing trouble with carter electric fuel pumps. I've fixed my fuel pump problem by putting in a Holley red. However, after installing the Holley, my 302 Pings at startup and while accelerating down the road. The noise starts out as a knocking then increases to a loud squeeling. I don't know if this is a timing issue or if it's a valve or rod. I hope it's not the latter. Ive been using 87 fuel for years and never had this problem so i dont think its the fuel grade. Any input will be helpful. Thanks.

 

So it knocks, then squeals? Does it misfire or blow smoke during this time? Can you smell fuel? The squealing is coming from inside the engine? What do the plugs look like? Have you ruled out that the squealing is coming from an engine accessory? Changing a fuel pump should have zero effect on valves and rods. Assuming you have fuel pressure enough for the motor and haven't run it so lean you fried the pistons the change in fuel pump should not matter.