With that cam and cubic inches, I would say the 185 runners will yield as good as you're going to get. Like others have said, smaller runners yield more lowend torque...and big runners take away that and puts HP on the high side. Those heads may be the happy medium you want. 100% agree with making up whatever you may lose on the bottom with a good gear/converter combo. FWIW, I run 180cc Pro Topline heads on my 360 cu in SBC and it pulls like a mule on meth.