I know what I need to in order to make this swap easy, except for one thing... My GT-S is an automatic, with a very smooth transmission. It's got right around 97k miles on it and shifts like a dream. Unfortunately, the engine is no good. Are the 5S-FE and 3S-GE flex plates the same outside diameter? If not, would I be safe bolting the 3S-GE flex plate to the 5S crank? I've got no problems having the holes closed and new ones drilled if that's what is necessary, but if at all possible I'd like to just use the 5S plate. I'd swap in another transmission to make it easy on myself, but the one I have now is a known quantity in amazingly good condition.