Thread: SBC Chevy flexplate

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What size of flex plate (153 teeth or 168 teeth) do I need for a 1978 chevy 350 with 2 bolt main. I am having starter problems and I think the wrong flex plate was installed!

My 1947 Chevy Project
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On another forum I saw this answer to your question -

Look at the starter. If the bolts are straight across (stock gm starter) then it's designed to work with the 153 tooth flexplate. If the bolt pattern is staggered (gm starter) then it's designed to work with the 168 tooth flexplate.

I can't swear it's true, but it sounds like the guy knows what he's talking about. As an alternative, I guess you could swap your starter based on the bolt pattern, assuming it will bolt up.

"........Look at the starter. If the bolts are straight across (stock gm starter) then it's designed to work with the 153 tooth flexplate. If the bolt pattern is staggered (gm starter) then it's designed to work with the 168 tooth flexplate......."

Yup.

As I recall a The starter for the 168 tooth when tried with a 153 tooth flex plate will not even engage with the flex plate teeth (but will bolt up).

I don't think you can even bolt up a starter for a 153 tooth flex plate to a 168 tooth flex plate as the nose won't clear the flex plate.

If the starter turns the motor over but grinds you might just need the starter shimmed a little. You also want to make sure you use the starter specific bolts.

On the bright side if it's just a starter/flex plate issue all you need to do is change the starter, not split the engine and trans to change the flex plate.


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starter shims are your friend! make a gage and set it. i found on our bracket car it was all important. broke a few starters before wising up.