I build my models as if I had originally ordered the car to my specs, so I would do the 326 4-barrel in this case.
That said, the 215 Pontiac looks a lot like the Chevy 230 painted blue and seems to be based on it. If you want that, do the research and adapt an AMT Nova wagon engine.
A friend had a 64 'pest 2 door post with the 215 for a while before the 2008-2009 crash forced him to sell it. It accelerated like fog and got dismal fuel economy.