I have a 408 BBC that will have about 9.850 CR and about 8.765 DCR. Is this O.K. for pump gas?

I would say no, it wont work. Roughly 8:1 DCR is the maximum safe limit for pump fuel and iron heads in all conditions. You can potentiall exceed that by a bit, or you may not even be able to run that much in some cases too. There are a lot of other things that play a factor in detonation resistance with pump fuel, such as actual engine efficiency, altitude, vehicle weight and so on, but your pretty high up there with the DCR number so if your calc is correct, it would be very difficult to make work. That would have to be a small camshaft....real small to get a DCR number that high with relatively low static comp. What are the specs for the cam and are you sure you didnt use the intake valve closing angle at .050 to do the calculation? If you did, than that explains it. You need to use the advertised intake valve closing angle, otherwise your final calculation will read much higher than it really is being that the IVCA at .050 is a smaller number than the advertised number. Post the rest of your engine specs as well as your vehicle and an estimate of its weight, gears, converter altitude and all that. If you are willing to make changes if necessary, than knowing the rest of this stuff will help the members point you in the best direction so that you can make the necessary changes(assuming so far that you do need to make changes).

Yea, that's way too high. According to David Vizard 8.5 DCR is about the max for pump gas. However, there are a number of caveats for that DCR. Vizard suggest 8.3 for a street engine. Personally, I think 8.2-8.25 is a good number. Greg likes 8.1 and others even lower. As Greg said, recheck your numbers. 8.76 is very, very high for the static CR you have.

I probably messed up on something then. I have a 408 BBC, 97cc heads, .038 head gaskets, KB160 pistons (17cc dome, .020 in the hole), and a Crane Energizer cam #103052. 272 advertised duration .515 lift,.Thanks for any help.

Using the numbers you provided and assuming a 110º LSA, 106º ICL, and 4.37" gasket bore I get 9.90 SCR and 8.087 DCR. With this cam the intake closes at 62º ABDC.

O.K. That sounds better. Thanks for the help you guys!!