If you've read the page that I posted earlier and downloaded the program you can see from the program that retarding the timing by 4 degree will decrease your dynamic compression ratio. The 292 cam that you listed may be a good choice for you. I assume that you are looking at the XE292 camshaft. Try running the numbers for that cam in the dynamic compression ratio program and if it's still too high try retarding it 4 degrees.
If you haven't built up this engine yet then using 400 pistons with a dish will help a bunch. In fact this is the best solution to drop the compression ratio. There are pistons avaiable with a D shaped dish from 16 to 30 c.c.s, these will lower the static compression ratio and let you be a bit more selective in choosing a camshaft. Do not use a head gasket thicker than .032 inchs thick if you can avoid it.