CMC_00

I have been searching the treads and haven't been able to find a definite answer to my question. I have a 2000 5.7L that I am putting into an '86 C-10. I am going with a TH350, but cant seem to figure out which flex plate I should be using. I have a torque converter with the longer center hub, I didn't want to have to use a flex plate spacer. I would rather not have to elongate any holes to get the flex plate to work, can someone post a link to which flex plate I will need? Thanks in advance for helping me out.