torque converter bolt grade

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Feb 27, 2011 | 12:14 PM

camarof41_383

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From: Danville, IN

torque converter bolt grade

I'm getting ready to install my engine and trans into my car. I'm using a Circle D converter and sfi approved TCI flexplate. The bolts that came with the converter are 10.9 grade but are too short (made for a stock style flexplate). The TCI flexplate came with the correct length bolts but they are 8.8 grade. I'm assuming its ok to use the 8.8 grade bolts since they came with the sfi approved flexplate but it concerns me that they aren't 10.9.

Any opinions on this? I want to be sure they don't break, this will be going in a low 10 sec car with a trans brake.

Or does anyone know the ARP part # for the 20mm long torque converter bolts if I decide to replace them?

Feb 27, 2011 | 02:28 PM

Vince B

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From: Bloomingdale Illinois

Grade 8 or better are fine to use.

Feb 27, 2011 | 05:52 PM

Jays_SSZ28

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Metric Class 8.8 is equal to SAE Grade 5.

Metric Class 10.9 is equal to SAE Grade 8.

I've used Grade 2 SAE with a big block and 4L80E.

Not sure how much shear force exists at the TC bolt and I've never seen them break except for when they worked loose and beat the crap out of everything.

Feb 27, 2011 | 07:50 PM

Circle-D

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From: Houston, TX

We recommend 10.9. We can send you some longer ones out if you need it. We have them in numerous lengths. Metric is sold in 4mm increments. So we have 12,16,20,24.....

Chris