Can anyone tell me where to find a evaporator coil for a 1970 Oldsmobile 98 Convertible?

 

Classic Auto Air or Vintage Auto Air. Both have a good reps. Ive used Vintage out of Tampa with great results. They should be able to find you used and aftermarket new.

 

If you haven't found one, try PartsGeek. They list them back to'77 Olds "98" for under $100. Also other GM Cars along the same year models might interchange, like Chevrolet ,Buick, Pontiac. I think Harrison made them for all kinds of GM. Larry