Engine info

Here's the info I have gathered on the engine
Block VIN
21X326471

Casting Code
485428

Block Code
6310287
YC
Code Car Year CID HP Trans RPO Carb Block Cast Main
YC F-body 71 455 325 Turbo 400 L-75 1x4 485428 2

Displacement Identification: 455

Date Code on Engine block
C 81 – March 8 1971

Head codes:

Casting # Year CID HP Valve CC
6X 1977 400 180,200 2.11/1.66 101

Head Date code – E187 (May 18 1977)