Check out these Profiler heads. BBC 24 Degree Sniper Heads 174 Series
. These heads are made in the USA. I would order them bare and have your machinist install the valves, and valve springs, retainers, and locks for your camshaft. If you are going to buy Chinese parts at least buy forged. Check with CNC Motorsports about a rotating assembly you will be better off than buying parts separate. Scat 1-42355BI BB Chevy 496 Competition Balanced Rotating Assembly - 10.5:1 Icon Dome Pistons - BB Chevy 496 Kits - Rotating Assemblies - New - Engine Components | CNC Motorsports | Car Parts | Truck Parts | Competition Engines
. I bought a 496 kit from them with the Eagle forged crank, Eagle H-Beam rods, Icon pistons, Clevite H-Series main & rod bearings, and Mahle pre-fit rings. I asked to substitute Icon forged pistons IC789-040 instead of SRP's. I explained that my block was already bored to .040. CNC Motorsports customer service was easy to work with. Check out the MSD 8360 unlike the Street Fire they have advance stop bushings to setup the mechanical advance. You don't need to worry about low end torque go with the Victor Jr. intake and a Holley 950 cfm. Stay away from thumpr camshafts they are all noise. Check out this Lunati hyd. roller 20110549K. Lift .578/595, duration @ .050 232/242 2000-6000. I think you will be better off waiting to buy pushrods until the engine is assembled and measure for pushrod length.