I've done a ton of research- so now I'm really confused....

My first upgrade would be a dual master cylinder for the brakes....safety first! (67 4 drum spec) Then valve seals and a 4bbl performer intake would be my first upgrade engine wise and a Carter/edelbock 600. I think these have more low end than a Holley. Your year 273 has the common bolt holes. Save the heads..the 360 sized '302's are actually 308's and youll dump the compression with those. If your gonna cam it up, call a cam hotline and tell them your static compression, weight and rear. They can recommend a cam around your lower compression. I put a Herbert 'stage 2' on a low comp 318 and it really was an upgrade without any low end loss. Love the color! Is that silver or light blue?