T350 Flexplate with a stamping . . .

[IZRSSS]

May need JohnZ opinion here, but I believe the three dimples identify the flexplate as part of a Variable-Pitch Trans. They are also there for F-Plate to Converter Orientation... I believe the raised dimple-side goes towards converter.

[tom]

I remember the Buick variable pitch trans, did Chevy have one ?

[IZRSSS]

Not sure about the T350, but I'm almost certain the Powerglide ST-300 did.

[JohnZ]

Not sure about the T350, but I'm almost certain the Powerglide ST-300 did.

What's a Powerglide ST-300?

[IZRSSS]

John,

Did some more on-line checking. Tom is correct, these transmissions came on Buick's. The ST (from what I've read on-line) is a Super Turbo transmission found in the 442. They are also used to convert a T350 over to a 400. My point is..from what I've read, it is the flexplates in these transmissions that have the 3 dimples shown in Ted's pics. Is there a chance his flexplates are for the ST-300 instead of the T350?

Again...this is second hand information from other forums this is why I suggested we run it by you. I would post the links but I have learned not to. 

[JohnZ]

I'm not very familiar with automatics (have never owned one), but I've never heard of a Powerglide with a variable-pitch converter used in a Buick.

[tom]

If I remember right, back in the 60's Buick used a two pitch converter in their 2 speed auto. It had an electric (I think) switch that changed the stall on the converter. Used for passing gear at highway speed, without kicking all the way down to first. It's been a long time, so my memory could be a little off, but that's what I recall. Also used by some modified by connecting the lead to the brake lights to allow a higher stall at a full stop, but switch it back as soon as you let off the brake.

[opelitis1]

Dug out a Book entitled Chevtolet Book of Numbers Volume 2 1953 - 1964 and if there is anyone who may be able to figure out what the heck a Group 10.469 is or was back then, apparently Chevy did not punch the total serial number of the unit, but just the last 2 numerics. In this case 42 is punched on the flexplate, but my book only states "plate" and that is it.  Plate for what???
Thanks!
Ted

[JohnZ]

Dug out a Book entitled Chevtolet Book of Numbers Volume 2 1953 - 1964 and if there is anyone who may be able to figure out what the heck a Group 10.469 is or was back then, apparently Chevy did not punch the total serial number of the unit, but just the last 2 numerics. In this case 42 is punched on the flexplate, but my book only states "plate" and that is it.  Plate for what???
Thanks!
Ted

Group 10.469 in the Parts Books has always been door hardware, and car assembly plants never stamped any part of the unit serial number (or any other number) on an automatic transmission flexplate. The "42" is probably the last two digits of the part number for the flexplate, or for just the spider stamping, less the ring gear.