Porting a 350 head still won't get you close to an aftermarket head because of the combusion chamber design and the flow that is built into the the Iron Eagles, Vortecs and others. New chamber design is so much more efficient that the old style, you can run more compression and build more power. Besides, porting is not cheap unless you do it yourself, and you really have to know what you are doing. If it was me, I would wait until I could afford exactly what I needed rather than try to make do with something less than ideal. A 383 will really make that El Camino move, and you will not have to run nearly as big a cam to make the power a comparable 350 would have to.