Heigth problem in flowering

I am using a Sunhut XL which I believe is 7 ft tall inside.With my hood,filter,etc I figure I got about 6 useable ft.I just put my girls into flowering last week and they were about 3.5 ft tall in the buckets.Since Ive put them into flowering most of them have managed to shoot to around 5.5 ft tall.How they sit right now a few of them are a couple inches from the light(600w HPS).

I still got 6-8 weeks left and Im running out of space.

My questions are:
Is it too late to employ some form of LST?
Or can they be topped this late in their life?

Strains Im growing right now are:Blue dream,Strawberry diesel,White widow,and Super silver haze.Im using a 600w hps light and the plants are in waterfarms.

I would just try to tie down the plant as much as you can while it is stretching. I ran into the same problem in my current grow and my main cola is currently fairly horizontal but still looking happy. I am using an LED light though so I suppose I can get it much closer without adverse affects. I wouldn't top if you are in flowering, let the plant do its thing.

always plan for the plant to grow 2-3 times the veg size by time done flowering. not a bad problem to have LST, trellis what ever it takes but dont cut herflowers will grow in any direction as long as conditions a good even down if thats were the light is.

Sure you can apply the LST method i am currently doing so right now as we speak. My girls are already hitting the roof. You can bend them slightly just be very careful you dont break your stalks. and also time them up to the bars in your tent away from the light so they do not burn. you should be ok.

I just topped a plant yesterday that had been in flowering for three weeks and had doubled in size. If it is still very early in flowering I say that topping will work and won't have any adverse affects. This said LST will probably put less stress on the plants.

You should not have vegged them that long. If you have limited height, most people suggest you start on the 12 hour cycle when they are 1/3rd of the size you want them to top out at. With this formula, you are on target for 10.5 feet. What I would do is crimp the top over and tie it down.