Need a Mopar guru: 273 part-throttle ping driving me crazy!

Need a Mopar guru: 273 part-throttle ping driving me crazy!

Thanks for your reply.

66fs said
That is the original 273 intake, so no EGR. The Holley is a replacement for the carter 2 barrel. Looks like a "LIST" R7890 number?

What does "LIST" mean?

I found this, but I am confused: is my carb a 7890 or a 2280?

66fs said
If it pings with the vacuum advance disconnected, adjusting the advance will not matter.

Yes.

66fs said
The 35 is just for initial and total timing, you can go past that with vacuum advance. I would not go lower than 0 for initial timing. Does it ping if you set initial at 0?

I had it at 5 ATDC and it pinged. 0 and it pinged.

66fs said
What octane?

Unocal 92, then 100 (4 gallons) mixed with 92 (14 gallons).

66fs said
The vacuum adjustment is to add or subtract washers, can't remember which off the top of my head, inside of the removable vacuum nipple.

This is good to know. Once I get rid of the ping, I will adjust vacuum advance if I need to. But I don't think timing is the cause of the ping?

66fs said
Is the 273 solid lifter or hydraulic? Can you remember?

It's a '68 273. My understanding is that by '68 these had hydraulic lifters. Doesn't "sound" like solid lifters, either.