not mine, but close by if you need help - https://washingtondc.craigslist.org/nva/pts/d/vienna-1968-buick-gs-400-engine/7707402286.html Disassembled 1968 Buick GS 400 engine. I was starting to rebuild and I had to go a different way. I would be willing to sell it for less than what I have into it. I bought the complete engine, running when removed, for $300. I took it to a shop to be disassembled, cleaned and inspected to be sure it could be rebuilt. No warping or cracks to block or heads, got a clean bill of health. I spent $625 at the shop to hot tank, dis-assemble pistons, clean and inspect crank, prep heads for bronze liners, and removed broken exhaust studs. Oil pump and gears all ok. I have everything except the carb. I have all the shop paperwork. Ready to rebuild into 400 or 455. Takes the gamble out of buying a used engine to rebuild, it is something you know is good from the start.
The bane of the Stepchildren. Cost more to build a 400 and less options for parts. The 455 has more displacement and more options. Many have been swapped out to a 455 or 430 or even a 350.
If it was local so I could lay eyes on it and avoid shipping, I’d be interested but not at $750. Us poor ole guys with 400s… get no respect.
Just bore it to 4.187" (430), add Stage 1 valves w/relieved chambers to the Big Port heads and don't tell anyone. Devon
What's really sad is that it was machined by the best Buick shop around here, who is now retired. Now there's no shops within a days drive!