Who has the highest revving small block?

I never had it (360) above 6800. I love the sound of a screaming engine.
Mufer selection has a big play in sound.
If your planning on a high winder, choose high power handling components. I would suggest over building it... Forged slugs & crank, premo rods, matching valve train parts recommended by the cam maker.

I love it, 273 4 speed went regularly to 7K, spoiled for life. Most everything in a small block motor will be good to 7K. Make sure your machine work is spot on, good rod bolts and size the big end of the rod most importantly. I prefer forged pistons, good rings, balance the motor, an ignition and valve train good to 7K, talk to your cam company. HV HP oil pump, windage tray. In my opinion, past 7K everything changes and big money comes into play. They sound great and pull strong. Goodyear radials burned through 1st, 2nd, and halfway through 3rd with 4.10 gears in a 64 Barracuda.