Flex Plate Question

[500/600]

If you are working on a small block Chevy (not sure what you are working on), and you are buying a new flexplate, then you better either buy it in person or ask prior to buying because many of the SFI plates have one round hole and two slotted on both big and small patterns. Many have round holes that are at least 1/16” oversized. Or save your money and use what you have.

 

[oldsmobile joe]

The odd thing is 2 of the holes are 1/2" and one is 7/16.

this is normal.
the smaller hole is the master index hole. start with this hole and fully tighten converter bolt. then you can install the next two. the over size or elongated holes allow for slight variation or allowances that may occur in manufacturing of flex plate holes and/or convert nut lugs.

and remember to apply a thread locking compound to the convert bolts.