My 68GS400 had a 430 decal under the 400 decal on the valve cover from the factory, does that count at a 430. The weird thing about my 68 is that the VIN is stamped on the back passenger side of the block. The factory worker must have had a bad hangover that day.
So I talked to the original owner and he confirms that he never had engine issues he picked it up from what used to be Mount Joy Buick in Hanover Pa. He said it always ran really well and he traded it in for a new Formula firebird in 1972. The lady I bought it from must have gotten it from there. By hearing the story from both previous owners, it leads me to believe that the 49xxx miles on the odometer is also correct. The only gray area now is what could have happened from the time it sat at a Pontiac dealership until the time the nice lady bought it. The dealership was L&M pontiac, also in Hanover Pa. But is long gone now....I live about 5 minutes from Hanover, so its cool that the car has been local all of its existance....
The 430 is a 67....and the car was built and sold in 67....so it could be possible...? There were no stickers on the valve covers, so no surprises there
I think you're onto a mystery that begs to be solved. My '69 GS 400 turned out to have a 430 in it as well! I got "the surprise" when I tore it apart in the early 1980s to rebuild it. Lo and behold, I found "430 1383424 GM5" on the rear of the block. I am unaware of any previous owner replacing the engine, although I had assumed that was the explanation for the 430 being in there...until this thread, where it turns out there are others like this. Maybe an engine installer on the assembly line showed up to work drunk, and put a bunch of 430s in GS 400s>. Or as a prank. It would be interesting to find out which plant the "mismatch" cars came from--what if they all originated at the same plant? My car came from the Fremont plant.
If it is a prank....i kind of like it. It is bigger than just Fremont, mine was assembled in Baltimore. Maybe the 400 in GS400 is a name and not necessarily the engine size....kind of like the Olds 442, they didn't all come with 4 speeds. Or, maybe as you said, a lot of Monday morning hangovers....
Its more like a case of supply and demand, Their were probably more 430 motors built than 400 motors... Just how many gs400s & SWs built in the 3 years... VS B & C bodies... I dont ever remember a 400 in a B or C body cars.
That is a good point. And at the time, who would have cared enough to ever check the number code when taking delivery of their new GS400? The factory may have figured "No one will ever know or care that we gave them a bit more displacement than they ordered." And if some cars ended up getting worse MPG than the factory claimed, this could be the answer.
If the engine is stamped with a matching VIN and the date codes make sense you have a case, otherwise who knows what happens to a 50 year old car before you owned it.
True. Any VIN-related stamped numbers had been milled off the block of my 430 before I bought it--it had some serious amounts of milling done to the deck and the heads. But my car was only 9 years old when I bought it, so I assumed it was the original engine. Odometer says about 1500 miles, which has obviously turned over, so yes, a previous owner could have destructed the original engine, acquired a '69 430 from the junkyard, and installed it.
Agreed. I'd bet a cold beer the original engine popped and was simply replaced. Lots of shady things happen at dealers, even new car dealers!
