[Chiefkey]

Just a follow up to the question and the great info I got from TXSTARFIRE. Looking carefully in my 1969 GM Parts book, I found a definite answer on
page 0-47. Under Group# 0.666 Part # 9772675 is listed specifically and only for a 63 T/8 A.T. Plate, Flywheel Reinforcement. I guess that settles it. They may have discontinued it's use in later models, but the 1963 Tempest V-8 w/automatic trans did use a reinforcement plate ! Also as TXSTARFIRE indicated they used Part #
544884 flywheel bolts (1/2" - 20 x 3/4").

[johnta1]

Service Bulletin:





One thing is that your 63 does not use a Turbo Hydra-matic. (I don't think anyway)

[Chiefkey]

Thanks John...those Service Craftsmen News updates are a Great tool. What issue is that one in ? I only have late 62 through 63 issues I use for my Lemans.

[johnta1]

No. 3 July 1968 issue.

They are very nice to have for sure.

[Chiefkey]

John, your comment regarding the transmission type is spot on. The normal automatic transmissions, ST, TH350. and TH400 all used a flexplate mounted torque converter which would place a twisting force on the flexplate under load. The Tempestorque version of the powerglide had the torque converter mounted on a shaft behind the transaxle and was driven by a long shaft or "ropeshaft" as it is commonly referred to, that was bolted directly to the crankshaft. So, with this particular design there was never any twisting force applied to the flexplate (flywheel) except when the started motor was engaged. My guess is that the engineers were worried about metal fatigue in the thin metal flexplate when they switched from the older Jet Away / Slim-Jim design with an actual flywheel to the new Turbo-Hydramatic Transmissions. with only flexplate/ring gear set up for the new block mounted starters.
Thanks, JK