Need input from big cam users.

crackedback said

Drilling the throttle blades should be an absolute last resort. I've got/had bigger cams with more overlap than what you have, not a single throttle blade was drilled.

Take the carb off and see what the size of the transfer slot is. If it's more than a square in size, open the secondaries and close the primary side down.

Google "holley transfer slot" and look at the images.

Click to expand...

Crackedback,

Just got off the phone with the mechanic that the owner used. First the owner did not have him check the ping issue. The mechanic said he has not touched the engine other than oil change in over two years. He did offer that by memory he recalls the cam was an ISKY cam. He thought the lift was around 540. But I think it is more likey this cam. 280 Mega. 485 lift 280 duration. Lash is 000 hot. This should be fun. I think I will try checking all the valves and look for the one with the biggest gap and check the rest against that. Like a baseline cold and then run it hot and see if any are tight.

As far as the primaries. Hard to tell from the top, so I will have to take the carb off. They actually don't look that open though. But I did check and I have a full turn on the butterfly adjustment screw. Not sure if that tells you much.