[lukecp]

487X heads are a fairly rare find....they came on early '70's LT1 350 engines.....being a "X" casting, the intake ports are 10cc bigger than the standard 487 heads. They might already have 2.02/1.60 valves too. The combustion chambers are 75cc's though, so if you want high compression you would have to run a domed piston.

If they are in good shape, i would use them, especially if they have 2.02/1.60 valves. Pretty much, they are a open-chamber performance head. Vortecs will flow better.....and make more power though.