Everybody probably knows that I am not a fan of LEDs for acropora and clams. Keeping the whites low is generally a good idea since they have some harmful peaks/output in them that can burn and kill coral where more than twice the output from other light sources will not - this is bad quality thing, not a quantity thing. However, if the clam is not showing any signs of burning, then it is not too much light.
Clams are a bit different than coral. They can digest excess zoox since they have a digestive tract and there is virtually no way to over-light them... none that anybody has found even with 1500-2000 PAR light sources showing no signs of shutting down photosynthesis - keep in mind that the PAR a few inches under the water in the Pacific is sometimes over 2000. You need to acclimate them a bit, but they can handle more light than you can give them. However, I have no idea if too much bad LED can burn clams too. My gut guess would be probably, but I do not know for sure.
Don't believe anybody that tells you that 160w Razor is as much light as a 400w Halide - there is too much to go into here, but it is either a total lie or they people just do not know. In the end, you would need 3 of those Razors to truly replace a single 400w halide, most likely. Once you consider the entire spectrum, and not just the visible range captured by a PAR meter, there is about 2-3% waste in a MH to excessive IR above 850nm, but then you need to match the rest watt for watt to do the same thing. There are no other real efficiences, just perceived by using misleading devices like LUX and PAR meters... and a lot of BS from a manufacturer.
Bottom Line: there is no way to give a clam too much good light. The only argument that can be made is too much bad light, but I do not know enough about the Razor to know how bad it is and which whites that they use.