that link shows FlyWheel bolts for a manual trans. I like the idea that they are longer than flexplate bolts so a flexplate spacer isn't a problem when using a mid plate. But i have 2 questions.
is that the part# you bought? Flywheel bolt heads/shanks work with the flexplate and spacer or is that just a random one you posted from Summit's site? did the shank under the head clear the shim and flexplate?
Did you have overhang through the crank that had to be shortened? (were those flywheel bolts actually too long by a little bit?)