How much will i yield? picss

First of all your yield is going to be very dependent on genetics. Are all 5 females? If you get 140 grams dried bud your doing good IMO, especially flowering with MH which still works, but not as well as HPS. A big plant just has more lower areas which will not get the light they need and will be fluff buds, the top colas are where you will get the most real buds.

Well i have another 400w MH light and another 175w MH.. im wondering if i should also use one of those? say i put the 175w at the bottum shinning up, or on the wall shinning sideways. What are some ways i can create a higher yield?

If you can handle the heat get as much light in there as possible. Good co2 levels also help and make sure that you are using quality nutes. Other than that I would just remember to keep them a bit shorter next time. Higher quantity shorter plants work much better under 400w lamps, try to keep them to 2.5 feet or shorter, which means you should start flowering around 12 inches or so, even shorter wouldn't be a problem if you increase the numbers.

Yes bring in all the lights, but make sure you have them shining down on the leaves. Plants can't use light that shines up though leaves AFAIK

You could get better bulbs more suited to veg for those halides. There are bulbs down to 5000k and lower and there are also pulse start halide bulbs which are superior to HPS for veg, but not all fixtures can run a pulse start bulb.

Either way MH is completely fine for flowering if that's all you have. Not the ideal spectrum compared to HPS but the yield will be good.

Next time don't grow them so big with small lights, you're counterproductive doing that. A higher number of smaller plants in the same space would have been better.