Firstly, I don't think it's Claymore's responsibility to field your bios modding questions. If you have an issue with errors for functionality in his miner then sure, ask him.

Also, your question is worded quite vaguely so it's hard for anyone to provide truly meaningful advice.  For instance, you say your are "not even getting 700 H/s with 4BG 470/480s".  OK... that could mean that you are getting 690 with a 470, which is actually about the top I have seen being reported (confirmed), including myself, and that is indeed with the 1500 memory strap bios mod.

Generally, 470's will get about 570-580 un-modded and around 690 after that strap-mod. I have 1 rig in each case, and that is almost exactly what my 470's are getting under both scenarios. Granted, 480's should probably do a bit better than that but not my much.

If you have not modded your GPU's bios yet, you simply need to google or search this forum for your exact card brand and model, as this can make a big difference and if you mod it with the wrong one you will likely brick it.