6.4 Valve springs on a 5.7?

Anyone done this swap? I am looking to use them to do a future cam swap, and picked them up real cheap. I have done a lot of google searching, and only came up with one Ramforumz posting that state 5.7 springs have an installed height f 1.8" and 6.4's use 2.01" (something along those lines). Comp cams states that only adds 5 lbs of pressure to the springs and is no big deal.
Any idea if this will work for an aftermarket cam swap?