A 408 generally will appreciate the extra cam duration. You could retard your current cam several degrees to shift the emphasis to the top end a bit.

Your current Edelbrock Cam, #7177 is 234/244 112°LSA 107°ICL.
It has a intake closing point(@.050)of 44°.

As most cams do, I would imagine that the solid Isky has 4° advance ground into it, so with 254/254 108/104, the intake closing point would be 51°.

If installed at 104°ICL the Isky cam will lower your dynamic compression ratio, but would probably be an improvement overall imho. It might not care for the 3500 stall at this point, though. You could install it early at 102° to help with the torque and dynamic compression ratio a bit. This would put your intake closing point at 49°