1963 Pontiac Super Duty Engine Codes

Code	Cubic Inch	Horsepower	Transmission	Carbs
12-5	421	390	4-speed	4	H.O.
12U	421	390	4-speed	2 x 4
125T	421	390	4-speed	2 x 4
13-5	421	405	4-speed	2 x 4
13-4	421	410	4-speed	2 x 4	SD - SC
75-9	421	410	4-speed	2 x 4
13U	421	405	4-speed	2 x 4
135U	421	405	4-speed	2 x 4
24U	421	410	4-speed	2 x 4
08B	421	353	3-speed	4	H.O.
11B	421	370	3-speed	3 x 2	H.O.
12B	421	405	3-speed	4
13B	421	405	3-speed	2 x 4
25G	421	353	Auto	4	H.O.
28G	421	370	Auto	3 x 2	H.O.
47Q	421	353	Auto	4	H.O.
50Q	421	370	Auto	3 x 2	H.O.