Contact the folks at Ad Performance they will tell you the best head for your application. Yes 205 heads would work much better on a 392 than the 185, thats why it would be good idea to talk to a teck. Give them all your info, pistons & specks and wether you are running a power adder? will make a big difference in head selection also. My engine is only a 347 so 185 heads were enough.
http://www.adperformance.com