bylkins Brent I see you are looking for 7,000 rpms and high HP. Doesn't your buyer know that TORQUE moved his car and HP is just a by product.
If looking for a quick revving motor, going to titanium rods would save alot of weight a\or even aluminum rods if he is told about heating up the motor first before beating on it. Are you going with a roller bearing motor for the camshaft? Lifters are .904"? Pac and Comp have new beehive springs out but are limited in the .700" lift range with a min coil bind.
I don't see why guys are not looking at 4.280 bore motors with 4.375 crank shafts. We have a couple of guys here racing and these motors make stupid power 760-800 hp and also run to 7,000 rpms but not recommended. Piston speed gets a little high. This is my next motor with TWM 58mm
I also have a set of stage 3 heads with KC ports. I got 368 on intake with 11/16 valves. I am looking at 8mm intake valves at 2.25". will stay with 11/16 on exhaust. I don't see a great differents between the 2 unless more work is done on multi vale angles. The valve where not back cut only 3 angle setup. You can pickup 5-10 cfm in the low range with cut back. I am going with a little stronger beehive than the old 126 springs for BBC motors. These springs do drop off at about 5,800 rpms with hydro lifters. Trick here is to have them pump up and run total.015" valve lash. They will still lose power to 6,200 but not like the correct adjustment or hit the pistons. The other help is running 75-80 psi of
oil pressure.
Hope your guy is going dry sump or an accusump pre oiler. Sound like a good build. Looking forward to seeing it. Rick. Ps that street twim works great. Going to buy another one for TA.