i have an 82 olds cutlass.i put an chevy big block in it.want to use my 350 trans. but i cant find torquconvetter to fit my flex plate.my flex plate is 14 1/4 in.the bolt holes are 10in.the torquconvetter i have tryed are 9 1/4 in. bolt to bolt.what do in need to do.change trans.or flex plate.