I am getting ready to upgrade my 350 TBI with a 454, also TBI. I want to retain the 700R4 trans which in my mind, is my biggest concern ECM-wise. I have searched and found others making this swap but with a TH400. Any advise would be appreciated. For those who may advise against keeping the 700R4 due to strength issues, I have built them before to withstand the TQ and HP of a big block.