Abento,
I don't think there was ever a Pontiac motor installed in USA built Chevy truck. However, wierd things happened to the North, South and East
From the beginning, 1911 to 1959 Chevrolet only used their own motors in their trucks with the expection of the 322 Buick used in the mid to late 50's. The 322 was needed as a "stop gap" (to keep pace with Ford and Dodge) in their "new" Heavy Duty line of trucks. So, starting in 1956 they borrowed Buicks tried and true 322 V8 that made 200 hp while the R&D Department was developing a "new" truck motor. The "new" motor became available in 1958 and was the 348...fondly nicknamed the "Stump Puller".
The 322 was only used in School Busses in 1958 and 59. I believe it had to do with not putting a "new" untried motor in a bus full of kids, but I could be wrong on this theory...
After 1959 Chevrolet would use different motors in their trucks, like the Detroit Diesel...
Happy Holidays,
Mike B
