1972 Duster - Very nice
Are those six pack carburetors from a Corvette?
What's CFM are they?
Reason I ask is the fuel lines are feeding on to the wrong side of the bowls to be a Mopar carburetor.
Beautiful car by the way.
Yep - she's a real head turner.
The carbs? Funny you should ask, not many folks pick-up on that. Those are some special carbs, and they contribute nicely to the cars originality. Corvette carbs? Nope. It's my understanding that these were originally designed & intended for a Ford Nascar race program using a high-reving 289 Cabra. Holley build the agreed Lot of X-amount of carbs, but Ford backed out leaving them in the lurch. Holley approached Mopar, who agreed to take them and added them to their old Direct Connection catalog as race-only, can't recall the date range (early 70s?). They use a 'mechanical progressive-link setup to open the end carbs, while the
Mopar six-packs are all vacuum actuated. The float bowls are different as well, with the float pivots on the side vs the center pivot for Mopars.
All 3 carbs have accelerator pumps, thus with these carbs, wow, fuel is right there right now! I've ridden in numerous six-pack Mopars (340/440) and they always felt a bit sluggish 'waiting' for the end carbs to open, actually feel doggish compared to these. These run on the center carb until about 40% throttle, and pressing further you feel a definite spot of increased resistance, like a stop. Look at the pic of the linkage.You press further into it and the end carbs immediately start to open, fuel is squirt'n, the car just jumps and that 'whoa' smile is spontaneous. The cam was ground for these carbs, and has a pretty tight overlap so there's plenty of manifold vacuum on-tap.
There's quite a bit of info in the web on these carbs if you hunt around, here's a link that speaks about them (
mechanical six-pack carbs. | Moparts Question and Answer | Moparts Forums). The thread is a fun read, and like most, it's not 100% accurate, like the cfm spec: research showed consistently finding the center is 355 cfm and the outboards 500 each.
It took about 9 dyno pulls to dial these in correctly. It made a high of 437 rwhp, but we pulled-out a little timing & tweaked the outbd carb accel-pump cams for better street manners, settling on 429 rwhp, good idle (still lumpy) and a snappy throttle (manual trani). A LOT of thought and work went into this car, and when you ride in it, you know it.
Hope all that helped - 'now please buy my car', ha, ha... Everybody loves the thing but I haven't even got'n an offer... strange days. Thanks for the questions.
