Most of the stock converters use a tiny 5/16 Bolts
I believe ONLY the Hemi uses the 7/16 Bolts
Nearly all aftermarket converters use the big 7/16
There are several different Flex Plates for different size
Converters 10 3/4 or 11 3/4.
Do you have a Stock or Aftermarket Converter?
The converter bolt are a special = Small Head fastener.
I doubt that you will find any Hardware store bolt that
will NOT HIT the Block!
Any Pick a Part or many Wrecking yards may have many small
converter bolts = They are very very common
We I get done racing and am home = pay for the envelope and I will
try to find some bolts and give them to you for free but that is as cheap
as I will go!