Big Block Mystery
#1
Big Block Mystery
I have what appears to be a 455 Big Block, casting number 398021Fa with partial VIN on the block of 33m335268 which indicates it should be a 1973 but it has A heads. Does anyone have any ideas on this or is it as simple as someone has installed A heads on a newer engine.
#2
#4
I don't think it really matters. Anything could have been changed or nothing could have been changed since the A heads show it's not original. If you are trying to make more HP then most important would be the Compression Ratio. If it matters, get a boroscope and look at the pistons through the sparkplug hole. If the block is really a 1973 and has original pistons then you have low compression. A 1973 block is just fine. It's what you put in it that matters.
#5
3 Olds Division,
3 1973,
M Lansing,
335268 the last 6 of the VIN of the car that rolled off the line with that block.
I don't think you can devise any other information with any degree of certainty from that number.
3 1973,
M Lansing,
335268 the last 6 of the VIN of the car that rolled off the line with that block.
I don't think you can devise any other information with any degree of certainty from that number.
#7
The engine most likely came out of an A-body car. Lansing assigned blocks of sequence numbers to each platform. Typically the A-body cars got sequence numbers between 100001 and 400000 in that year, but there have been documented exceptions.
#9
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