Help decoding my engine
Thread Starter
Instructor
Joined: May 2021
Posts: 160
Likes: 27
From: Yukon, OK
Help decoding my engine
I have a 1968 that has had a big block dropped in it along the way at some point. I am hoping you all can help me figure out exactly what it is that I have. I was working under the assumption that it was a 427, but would a 1971 date make it a 454? Is there any way to determine compression ratio or HP from the info below? 2 or 4 bolt? Thanks in advance for the help! Lee
- 3963512 - on left side of block in front of bell housing
- P - between code above and bell housing
- GM T7 - to the right of both the above codes and in front of bell housing
- D 6 71 - on right side of block behind distro and in front of bell housing
- CE 171643 - on right side of block behind water pump
Le Mans Master
Joined: Nov 2001
Posts: 8,571
Likes: 1,847
From: LONG ISLAND
2025 C3 ('68-'73) of the Year Finalist - Unmodified
2024 C3 of the Year Finalist - Unmodified
2023 C3 of the Year Finalist - Unmodified
Well start with "CE" it's an over the parts counter Chevy dealer "REPLACEMENT BLOCK"
Was the 68 originally a 327 ? or 427 ? just curious ?
Was the 68 originally a 327 ? or 427 ? just curious ?
Thread Starter
Instructor
Joined: May 2021
Posts: 160
Likes: 27
From: Yukon, OK
Correct, it is a warranty exchange block. I don't have a build sheet, so have deduced based upon lack of tell-tale BB suspension parts that it was originally a 327.
Le Mans Master
Joined: Nov 2001
Posts: 8,571
Likes: 1,847
From: LONG ISLAND
2025 C3 ('68-'73) of the Year Finalist - Unmodified
2024 C3 of the Year Finalist - Unmodified
2023 C3 of the Year Finalist - Unmodified
