B&M sell a SFI rated race flex plate which would be best,others have them as well and check out jegs and summit racing for more details.Also upgrade to larger convertor bolts too,and have the convertor drilled and tapped to fit them.As a example: drove a freinds hemi dart and we started to hear this weird noise and all of a sudden no more tranny due to the fact he was still using the stock convertor bolts,and had sheard off all the bolts and broke the stock flex plate,not good,mrmopartech