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

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I agree 100% with the exhaust leak/exhaust noise theory. Mopars are NOTORIOUS for making all kinds of exhaust noises and having leaks at he passenger's side exhaust manifold when the hot air valve is still in place. The bushings wear and allow a little leaking and it can sound exactly like spark knock. If the valve moves very freely and has ANY lateral movement, I would consider that the top suspect.
 
66fs said:
Cast iron, dual point, ball bearing vacuum advance Prestolite distributors only came on Commando / Charger 4 barrel 273's. The "Correct" 68 273 would have open chambered heads like the 318, slightly taller flat top pistons with 4 valve notches, a standard Chrysler distributor, and hydraulic lifter cam setup. What you have, may or may not be, a stock 273 2 barrel from a 1968 Belvedere. Closed chambered heads are typically less prone to detonation, but in a 273 closed chambers will give more compression. Which is going in the wrong direction for you.
Click to expand...

Every 273 I've ever taken apart, most of which were 2BBl engines all had closed chamber heads which use 5/16 bolts on the intake manifold. I just recently received a pair of heads from a 68 Dart 4dr 273 2BBL car which also had the solid lifter cam and adjustable valve train. I've never run across an open chamber head that came stock on a 273....
 
I'll check the casting numbers on these but I know they are closed chamber. I have seen some 273 hydraulic stamped rocker engines but this one also was a solid lifter engine.
 
I have a question (feels like I am derailing [back] my own thread... :D )

Are Holley jets pretty much all the same? I may be more interested (if I have to go into the carb, anyway) to just swap the jets for something a little larger to get a slightly richer/phatter mixture rather than drilling the current jets. I see Holley jets on their website but not sure if they will fit/are universal amongst all their carbs or if the 2280 needs a different kind of jet...

Thanks (back to y'all)!
 
did you ever run a compression test to see where it is? 150/180/200psi?
 
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