# engine Block codes



## HenryJ63 (Jan 11, 2010)

Hey All, dumb question.

I see that the two letter engine codes are for different engines and transmission type. What is needed to put a manual trans behind a auto block? Different counterbalance to compensate for flywheel weight vs flex plate?

Is there a difference in bellhousing bolt patterns?:confused

I have been working on Rotary engines for so long now I forget.

Thanks,
Hank


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## injn37 (Nov 16, 2008)

You can bolt up a manual trans bell housing to any motor (Pontiac). All years fit, although starter mounts vary on early motors.
All Pontiac motors are internally balanced. Hence, all external parts are neutral balanced. You can bolt a flex plate/torque converter or a flywheel /pressure plate/clutch up the to same crank, no problem

rich


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## HenryJ63 (Jan 11, 2010)

Thanks Rich, I thought that may be the case. One more question;
are Pontiac timing chain marks both at 12 o'clock instead of a chevy at 6&12. Last time I did a Pontiac timing chain was 1982 and things are a bit fuzzy....Then and now LOL


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## Too Many Projects (Nov 15, 2008)

Normally, the marks on the gears face each other for install (6&12) but you will want to turn the engine over by hand 1 revolution to determine the compression stroke. I have seen a LOT of Chev timing marks on the exhaust stroke....


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## Rukee (Feb 8, 2007)

:agree and to add, I'd drop in the distributer after you get the #1 cyl on TDC.


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## 646904GTO (Feb 10, 2008)

Too Many Projects said:


> Normally, the marks on the gears face each other for install (6&12) but you will want to turn the engine over by hand 1 revolution to determine the compression stroke. I have seen a LOT of Chev timing marks on the exhaust stroke....


Ironically I have seen many Ponchos cranked 180 because the mechanic was a chebby guy.lol They are 6&12 The Pontiac is 12&12.


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