AFR 245 heads are pretty stout and outflow stock LS3 heads - doubt you'd make 500rwhp but I bet you'd be a solid 430-450rwhp

that being said - I got my L92 heads for $600 as a pair loaded with valves and springs shaved .030 for 65cc chambers

AFR 245's are prob $2400+ range

 

Skeet was close to 500 on motor with his lq9 with an ls3 topend.

 

Took me a while to find his exact setup - but he had heavily ported l92 heads and an lsxr 102 intake with a much more aggressive cam and an electric water pump

"anyway right now i consist of a stock lq9 rotating assembly, with l92 heavly ported heads, with hollow valve stems, 660 lift double springs, a 232/238 advertised at 230/236 cam, the FAST LSXr 102MM intake and throttle body, electric water pump, e-fans, 4400-4600 stall which flashes at 4500, stepped kooks headers 1 7/8s-2 inch headers, dual 3" exhaust into 2 xr1 borlas, 4l60e performabuilt tranny,detriot true trac 4:56 gears, last dyno i put down 480+/440+. oh yeah and its 4 linked, with fuel cell and race seat"

 

500 to the wheels all motor is going to be expensive and impressive as hell and alot more than just engine work will be needed... especially to make it live..