Cost of changing fifth wheel

I’ve just changed trucks, and the replacement is the standard uk hight 1250mm fifth wheel.
It’s got a slider and is running on 295-80 tyres.
My last truck had a fifth wheel hight of 1150mm and ran on 315-70
I would like to get my new truck down to something like my last one.
Anyone know the rough cost of lowering the fifth wheel,I don’t need a slider.will I need to buy a complete new turntable or can I just change everything but the turntable itself.
Also,is changing the tyres to 315-70 an option,I realise I will need to do the test station thing if I do.

you can change the feet on the 5th wheel, they come in 3 or 4 different heights, somewhere between £140 to £180 if i remember correctly, should only be a couple of hours labour on top…

lrm

LRM:
you can change the feet on the 5th wheel, they come in 3 or 4 different heights, somewhere between £140 to £180 if i remember correctly, should only be a couple of hours labour on top…

lrm

Ok cheers.
I shall make enquiries.