Year Engine HP Engine code Trans CR Cam Head Code BBL Carb No. Misc
1968 428 375 HP YH A 10.5 067 16 1-4 7028268 GP Block Casting # 9792968
1969 428 360 HP YH A 10.5 066 46 1-4 7029268 45 deg int. Bonneville Block Casting # 9792968

When you look at the VIN on the block face next to the timing cover, you'll see that it does not match your car. The 428 was not dealer installed (that it has a YH code, a stamped engine unit number that does not match your billing history, and the VIN will provide the trifecta) but it's a great combination. Congratulations on a nice find!