What do you think about this flex plate?You have a 2 piece rear main seal block which uses a neutral balance flexplate, as long as the block has the two straight across holes (red and blue) you can use either a 153 tooth or 168 tooth with mini starters that have a dual pattern. I always use the 168 tooth since I feel it gives a little more room accessing torque converter bolts.
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https://www.summitracing.com/parts/sum-g100sfi/overview/make/chevrolet