I have seen the dual pattern GM automatics, but the Toronado/Eldorado/late Riviera TH425 isn't your average tranny. It's a beast all on it's own. Never used with the Chevy pattern engine, so it doesn't have the upper holes. I suppose that you could make it work, but why not just use the engine it's designed for? Beides, I've driven a '76 Eldo with the 500 inch engine. Let me tell you, that thing accellerated like a rocket!
