[glhs#116]

Just for giggles, here's the carb info. My carb is a 1972 unit for a 455 with auto but is not the HO unit. It's 7041262. I rebuilt it with a kit from Cliff a little less than two years ago. At the time it was still the old cam and heads.

Carb had been 73 jet with 45 rods and BU secondary rods

Kit came with new idle tubes which were installed. Also two drill bits which were I believe:
.0625 idle channel restrictions
.1015 idle bypass air
Both were used. Afterwards I found it was too much idle bypass air and I partially filled the enlarged idle bypass holes with pieces of a roll pin which brought it back to a good place.

Kit came with 42 rods which proved too fat. I went up to 43.
Kit came with DA secondary rods (these are long taper, the BU are short taper). I installed these but they made the car fat and slow and I put the BUs back in.

So carb was 73 jets, 43 rods, BU secondary rods.

A few days ago I figured that Cliff knows his stuff and probably the new heads and cam move a lot more air so I tried the DA secondary rods again. With the new combo the DA rods are a BIG improvement on the BU secondary rods. However, since I've been mostly trying to dial out ping I haven't touched anything else in the carb yet. I will say, however, that "seat of pants" it runs and drives very nicely in all scenarios. I'm sure there's something to be gained on the primary side but as it is it's working well.

Also, since the detonation is the main topic here I should add that with the DA secondary rods the car picked up a lot of _power_ in the secondaries and was nicely responsive (it wasn't with the DA rods and the old cam and heads) BUT the swap had zero effect on the tendency of the car to _ping_ under full throttle versus the BU rods. The only difference was power. The ping sensitivity under full throttle was exactly the same from BU to DA rods.

Just in case it rings any bells for anyone regarding the whole ping thing.

Sam