not sure what your getting at there... but I'm simply saying what head I had a Minisport stg 3 head if I just said stg3 head then that would be stupid but I didn't do that.
anyway MS head spec is 37 in and 29 out mine has since been fitted with rimflow inlet valves this is an engine thats built and giving good figs just not delivering the power how I want it I'm not wanting to change the head untill next winter when it will be a 7 port but the MS head is quite good ok its not a MED race head or what ever but nor was it £600
That should be an excellent head as the valve sizes are large and the valves are the excellent Rimflow. That really is a top-spec head. Please reemember that I do try to give the best advice I can, but I don't have the technical specs of each company's head stages or levels, so your latest head spec is what is most helpful.
In fact, with that head, a 286 would perform well, although the final drive ratio might need to be lower to keep it 'on-the-cam' as max power would then be at around 6400 rpm. Wait until you get the 7-port. It will just fly along.