Yes the locked centres have had the spider gears welder together

I have no idea what ratio would be in your ute . . . sorry

There is two ways to tell the ratio of your diff.

first is to jack the car up and turn the tail shaft by hand and count how many times it goes round to one revolution of the wheels.
eg 4.11 turns of the tail shaft to one turn of the wheels.

the second way (and best) is to remove the centre from the diff housing and look at what is stamped on the crown wheel
eg. B37:9

which means the crown wheel is 37 tooth and the pinion is 9.
37 : 9 = 4.11 : 1

if by chance the diff in your ute is 4.625 : 1
and you want to swap centres you can choose to go faster by fitting the 4.11 or slower but excelerate quicker by fitting the 4.875 one.

Cheers,
Geoff