just wondering if 185/70r14 are too big for the rear ona 1200 ute? i know you are supposed to use either 17565r14 or 18560r14 but would there be much of an issue?

are you wondering about the width if so it should be right ive got 195s on the back of my ute on 15in trx rims

What is it that you are trying to achieve? This is the major question you need to ask yourself before parting with any real cash money.

The taller the tyre, the higher the overall gear ratio will be, which can be good if you are seeking a few less revs at cruise speed.
The taller tyre will also fill up the wheel arch better, which is also good if your ute sits up a bit high in the bum.

On the downside, the taller sidewalls will flex a bit more, which can be good for comfort, but not so good for fangin' it in the twisties.
The taller tyres are also a problem when used on the front as they can more easily rub fenders & footwells, so here's a little info to help things along.

The OD of the various tyres is tabulated below, starting with the stock original size for comparison.

600 x 12 tyre is 574 mm
185 x 60 x 14 is 578mm
175 x 65 x 14 is 584mm
185 x 70 x 14 is 616mm

Personally, i like the 185 x 60 x 14 for the front on 5" or 5-1/2" rims as they should provide all the grip,, & all the clearance you will ever need for front applications.

For the rear, in a ute with it's original 4.11 to 1 diff ratio, i kind of like the
195 x 65 x 14 at 610mm or even the
205 x 65 x 14 at 622mm.

If you want to stick with 60 profile tyres, then the
195 x 60 x 14 at 590mm or the
205 x 60 x 14 at 602mm or the
215 x 60 x 14 at 614mm may be the go,

My personal choice could easily be the 205 x 60 x 14 as this gives an increase in diameter of 27mm or about an inch. It also means that your ute will travel about 75mm, or three inches further foward with each rotation of the wheel. It works for me. If even taller gearing is needed, then switching to the 3.9 to 1 diff ratio would be my next step.

Check very carefully just how much room you have in there. A 6" rim, or even larger should work well under the back of a ute.
The advantage of big 'n' littles is that it gives the car a nice little rake, known as "rubber rake" or foward slope. Its a bonus.

Think many times about this before spending money as a mistake can only bring unhappiness for as long as it takes to wear them out, & that might take a while.

EDIT
All of the info above was sourced from my 1988 "Tyre & Rim Association - Australia" manual.

That thech data is exactly what i was looking for dodgeman, i have the tyres on the sprinter rims alrady, two worn to very good, cant aford new set so if i could get away with two 185/60/r14 on the front it would make me and my wallet(wife) very happy.
The offset of the sprinter rim is 25, compared to stock datsun 1200 12inch of 28 i believe.
I like the fats ant skinnys look, had 205/60r13 on the rear and 175/70r13 up front, no problems with celarance on rear unless carrying more than 200kg and the may rub on the inside at full travel.
the 175s are cactus though so better off with 14's i say!

I had 205/60/15's on the back of my ute and they fitted just fine.