Flowmaster 10 series

I bought a single chamber flowmaster other works known as 10 series. It is a 2.5" inlet and a dual 2.5" outlet. I installed it and put two turn
downs before the rear axle. So now my question is, Has anyone got this muffler and/or what should I do to fix the back pressure. I feel like it does not have enough back pressure but maybe I need to just finish the pipe out the rear so it rides better through acceleration. I thought about Y piping in to one pipe or just weld a delete over one of the outlets. NEED INPUT ASAP THANK YOU

 

Thats my question if it would be enough back pressure, how bad is it?

 

UPDATE: So after spittle toying around with my exaughst there is enough backpressure as long as you keep it single in single out.

 

Well then I might need to go get one id rather single in single outbut my magnaflow is super quite I need some rumble

 

If you do dual out it sounds like a ricer and you don't want that but you can tell that there is an after market exaughst on my pickup. I like the sound and I have a turn down before the rear axle.