1969 Olds 442

[Silverstrike]

They made a 455 too iirc.

Yes but not in 1969 for the Skylark but that all changed in 1970 and diff with the GSX. Plus I would think the big block Buicks would be out of his budget/price range.

 

[SecondhandSnake]

Secondhandsnake: How were the heater cores on the A bodies?

If they were, the OP can check the passenger side floor below the glove box.

If it's still an older one they're still probably the old copper style ones. Really robust. And if memory serves me correctly, it sits in a big module on the firewall in the engine bay. No need to rip out the whole damn dash.

Which also brings up another point- anything that old with an iron engine and standard green coolant that's been sitting can be pretty rough internally. Ask about the most recent coolant change/flush. If there hasn't been one check for things like freeze plugs rusting out, or worse still, the block itself.