If my 4346 Holley was correctly restored it would have #68 primary jets. They are what came in the car when new. I got lean surge at highway speed with this setup but it would pass emissions. Can't blame the restorer for that. Jetting up about 4-5 sizes made the world of difference. Restoration and tuning are two different things. Things like this must drive guys like Eric crazy some times.
If you only knew...LOL! :clonk: :wacko:
Actually, 98% of the time the factory calibrations are very close for everyday use. Many of the GM 780 Holleys were notorious for being a tad lean on the primary side from the factory, but I'm sure they were calibrated that way for the sake of mileage, emissions, and keeping a set of spark plugs in the engine for more than a month at a time.
And yes, restoration and "tuning" are two
completely different worlds as far as I am concerned.
While I built and "tuned" a lot of "hot rod" carbs 20+ years ago for the local crowd, 99% of the time I purposely stay away from those types of builds these days, instead choosing to focus strictly on the OEM restoration side of things. That isn't to say I won't add a little tweak here & there and deviate somewhat from factory calibrations during a restoration when its needed, as there are numerous applications which leave significant room for a variety of improvements.
But remember, the OEM's spent buckets full of $$$ refining these components to work in a wide variety of circumstances, and for the most part they did a very good job. With just a few very minor tweaks, these 40 year old factory carbs can work surprisingly well. :thumbsup: