I thought the Corvairs did have a chin spoiler starting in 65. If you dont have one I hear the 69 Camaro one fits nicely. Have also seen S10 air dams cut down to fit.
Definatly a vacuum guage.
Old cars are a hoot to drive, I drove my 66 Polara 'vert all summer and love the
I get. Wish mine got more than half the mileage yours does but even if you drive a 383/auto carefully it still guzzles gas.