I'm building several 72 to 73 BBD's for testing in my just installed Super Six setup.
This following has two different throttle plates; I've been putting in throttle plates without holes for the Super Six setup and bushings for the shaft so I have no intention of re-using these plates but there must be a reason for the difference?
http://tinyurl.com/ovbwzq3

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1965 Dart 110k, 225, Carter BBD Super Six, 2 1/4 single exh., sbp manual scarebird front disc, 7 1/4 rear 2.94 sure grip, 14 x 4.5 OEM wheels, 833 OD with hyd. throwout bearing, HEI, electric fan, ram air/heated air, Accusump. http://plymouthcarclub.com/

Reed the 1976 Chrysler supplement in the BBD repair manual PDF for the explanation of the hole in the throttle plates.

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Casually looking for a Clifford hyperpak intake for cheap.

Comparing these two throttle plates in a early 73 V8 BBD & they are different.
They carry a different part number.

Maybe a prior rebuilder mixed up throttle plates in the same carb?

I didn't find the 76 supplement for Super Six to discuss why the early 70's V8 throttle plates had this difference between them in the same V8 BBD carb?

I'm putting in plates with no holes for my Super Six application but I might be missing something that is important for this particular early 70's carb(low top which has external bowl vent cap/hose connection)?

From my Slant readings others have used the V8 carbs successfully...some changed the throttle plates to no holes....others didn't.

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1965 Dart 110k, 225, Carter BBD Super Six, 2 1/4 single exh., sbp manual scarebird front disc, 7 1/4 rear 2.94 sure grip, 14 x 4.5 OEM wheels, 833 OD with hyd. throwout bearing, HEI, electric fan, ram air/heated air, Accusump. http://plymouthcarclub.com/

What part numbers on those plates. 2-303 was common,for a lot of 318,s. One carb 6317A for 73 used a different plate 2-317.This plate used a lot in later years.Never seen one like that.Looks like it lines up with ported egr connection.

Here some info on 1973 carb http://www.imperialclub.com/Repair/Lit/ ... /index.htm

In this carb:
The 2-303 throttle plate has the hole in the center.
The 2-317 throttle plate has the 1/2 hole on the edge.

With both plates in the same throttle body section of the same carb maybe I'm thinking too hard.....it may be that a previous "professional rebuild" resulted in the mixup? ie the factory never made it that way.

But the fact that it lines up with the port* suggests a factory possibility?

Thanks for the 73 carb info...I'll take all I can get and devour.

* I made & bolted a block off plate at the egr valve location to discourage exhaust leakage/flow into the intake stream thru the carb.

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1965 Dart 110k, 225, Carter BBD Super Six, 2 1/4 single exh., sbp manual scarebird front disc, 7 1/4 rear 2.94 sure grip, 14 x 4.5 OEM wheels, 833 OD with hyd. throwout bearing, HEI, electric fan, ram air/heated air, Accusump. http://plymouthcarclub.com/

http://www.slantsix.org/forum/viewtopic ... sc&start=0 Some bbd links here

http://www.tocmp.com/manuals/Carbs/Cart ... index.html carter carbs specs

Around page 10 here http://www.imperialclub.com/Repair/Lit/ ... /index.htm The 73 fsm does not show a hole like that .The egr port should not have vacuum at curb idle.

Agreed the picture does not have a throttle plate notch in line with the port.
But I can't seem to see the hole in the center of the throttle there either.
The picture angle may block vision of that hole?

At this point I think it appears a rebuilder mixed up different carb throttle plates.
This is easily corrected when bushing the shafts.
In my case I'm trying throttle plates without any notch or hole for the Super 6

Thanks for your research & links.

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1965 Dart 110k, 225, Carter BBD Super Six, 2 1/4 single exh., sbp manual scarebird front disc, 7 1/4 rear 2.94 sure grip, 14 x 4.5 OEM wheels, 833 OD with hyd. throwout bearing, HEI, electric fan, ram air/heated air, Accusump. http://plymouthcarclub.com/