big block head castings

What you have are "516s". That last digit is a 6. Those heads have a fairly bad exh port, and a flat intake port. They come with 1.65 exh valves IIRC, and have issues with core shift. In stock form, I wouldnt expect much from them other than to help keep the comression up. I have two sets in service now that make 480 and 500 crank hp after a performance rebuild and midium port work. About a stage 2 porting job. They respond like any other head. Favorably with improvement, unfavorably with cheap work and parts. 110psi for a stock lower end and stock parts is on the low side of OK IMO. If they are all close to 100, I wouldnt sweat it.