Typical bracket guy isn't going to build a 318, bracket guy wants to go as big as he can as cheaply as he can.
A bracket 318 could have a head with 50+ cfm, and 3 points more compression than a Super Stock 318. $7K-ish would get it done.
I for one cannot see it taking 20 grand to make 545 hp out of a 318, a stocker, yes because they have to work with "stock" parts, no comp, stock 400? lift, stock intake. But ported heads, big roller cam, high comp pistons, with today's technology I think it would be easy but a very peaky engine with much rpm. 340 stocker engines are turning 7500 with stock J heads and intake with a TQ. Just read about a 273 running mid tens(and not a D Dart). Go for it, compression will be your friend.
A .060 over 318 would need 1.66 hp per cube to reach 545 horse, since we are NOT required to follow the paramaters of a superstock engine. How could a 328 cube engine with ported Ed heads, a .720 lift solid roller, Jesel or T&D paired shafts, and 13.5:1 compression not reach 545 horse at a reasonable cost?
I dont understand the doubting. As far as the rpm ceiling, way way back, my pops bracket raced a 340 powered car every week, shifted at 7200 and traped at 7300, had TRW 10 pound dome slugs, STOCK rods, Crane ductile iron rockers, and a flat tappet cam. So a 318 with strong lightweight honda journal rods, lightweight pistons and pins, thin ring pack, titanium retainers, roller cam and paired shaft rockers with excellent geometry there is no reason it couldnt withstand 7600-7800 reliably
