Not your Favorite engine Grumpy,
But Oldsmobile V8 engines have become Rare.
Not sure why.
They may be nearly gone now usable cores out there or running engines yet.
I have not seen them for sale hardly at all in the last 1 year.
Ebay or Craigslist.
425 is definite worth something in future or now( value unknown because absolute none are for sale complete as mine is and running).
Pontiac V8 still found pretty easy.
The Pontiac Performance guys have shifted to all Race engine builds. $40,000-200,000 engine builds the few out there like me.