what to do with my 273

It depends on what your trying to do, if you want to keep the 273 then add the 318 heads as they are a bigger port runner than the 273 and the valve is the same size. Clean up the bowls and do a good valve job and you should be fine. You may want to step the cam up to something in the 220 @ .050 range and .450 lift, this with a 4 bbl and you'll have lots of fun.

BJR Racing