421 in 65 Bonnie with twin carb and single exhaust?

Hello

I am the proud owner of a pristine survivor 65 Bonneville Convertible with bucket seats and a 65 Catalina 2ht as well.

About 13 years ago I bought a well restored 65 Bonneville Convertible that got hit by a truck!

The car was toast, but the interior and the rear half were perfect. The interior is in my Catalina now and some trim as well. Quite a lot of parts ended up in my Bonnie. I used plenty of parts from the vehicle. As I had to pull it out of a barn, I gave it to a strange guy who needed parts. He brought me some of the things he removed, the doors and the rear parts. this vehicle had the engine in it. But the hit took the water pump, radiator and everything in front of the engine out. It had a twin carb and a single exhaust. The guy claimed he could identify the engine as a 421. He kept it. I somehow doubt this bragging fool. Did Pontiac really built 421 with twin carbs and single exhaust? If the guy is right, he might have scored big. He took the car, used some parts for himself and will dump the body shell. And I have another big pile of good spare parts for myself,