My cat has 2 4 bbl and a 4 speed, and what I know unless you got trips it's a 421 , how do I find out ?

 

 

Are you wondering if it a 421 block? - I believe that they were available in 63 and if you have a numbers matching block you have a treasure.  Someone our there should be able to help you with this - you can probably get the serial # on line.  Sorry, but I don't know enough about the HI PO Pontiacs of the 60's except they were great cars.  My Dad had a 63 & a 64 Catalina, both were 2 dr hard tops - I loved them both.

You need ti find the block casting number. Early Pontiacs are on the passenger side. Mid-60s is near the distributor. Later blocks had the displacement stamped on the side. I suspect you don't have an uber-valueable 421 Super Duty, but I included it in the list anyway.

You could still have the 389.  In 1964 was the 1st year the starter is attached to the block instead of the trans, which would be the 2 speed powerglide. Still very sought after trans for drag racing.