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Rod difference between automatic and manual transmissions.

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MRSOFTE:
I have a 7028210 on my 68 325HP 396. The specs call for 71 jets and 49 rods which it has as the car did come equipped from the factory with a powerglide. But looking at a Rochester chart I see that a 7028211 which would be for a manual trans car, the specs call for 71 jets and 45 size rods. Assuming that chart is correct....why the difference?
Thx.

Ethan1:

--- Quote from: MRSOFTE on October 29, 2016, 04:44:08 PM ---I have a 7028210 on my 68 325HP 396. The specs call for 71 jets and 49 rods which it has as the car did come equipped from the factory with a powerglide. But looking at a Rochester chart I see that a 7028211 which would be for a manual trans car, the specs call for 71 jets and 45 size rods. Assuming that chart is correct....why the difference?
Thx.

--- End quote ---

 Remember, the differences between A/T and M/T Qjets were the jetting. So, that would probably correlate to the metering rods as well. M/T Qjets were ran leaner than A/T Qjets. This was necessary for the A/T, to compensate for fluid loss. 8)

MRSOFTE:
Ethan
Thx for your time.  But I'm not exactly sure what you mean by fluid loss? The Rochester list I saw (posted by Lars)
shows no jetting change between the two. That stays at 71. Its only a difference in the rod size.  I did swap in a manual trans on to my Chevelle last year. But never thought there might be an "internal" difference between the two carbs.
Just an external one on the accelerator cable side for the trans kick down cable/linkage pin thing.
However, interestingly. Just after I posted the question I was rooting around in the garage, and find a set of 45 rods.
So after installing them I head out. And the absolute first thing I notice, is there is no more deceleration burble. It was minor at best before and not a real concern. I also had a "hardly noticeable" soft spot when pressing the throttle at around 3000 RPM. That is now apparently gone.
I have taken Cliffs suggestions he has stated in this forum to heart and resisted getting one of the wide band gizmos. And just concentrating on test and tune by feel. Besides its more fun that way! And in my opinion a lot less confusing.

Ethan1:
 What I meant by fluid loss, was due to going through the torque converter. I didn't mean actually loosing fluid. :o

 As for the jetting, it all correlates together. Whether the jets are the same and metering rods are different or vice-versa, it is still the same. 8)

MRSOFTE:
Gotcha. But what exactly is going on in the engine for the factory to specify different rods sizes between carbs due to whether its automatic or manual behind the engine?

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