define "fair amount of power"?   would it handle 250hp and maybe 400nm NA or 350hp and 500nm+ with a turbo?   I'm not planning on drag racing the car or anything like that but it may get the odd back road run every now and then....wayyyy to many coppers out this way to be silly buggers.

if you rebuilt it before breaking it, or it's in good condition to begin with, it will handle a fair amount of power.  the V6 commo input shaft bearing is supposed to be an upgrade, but i don't know how it's fitted (is it full box teardown etc?)

I measured up the input shaft its the 6 cylinder one 167mm, the V8 one would of been 20mm longer if I remember correctly.   Doesnt really matter at the end of the day...a T5 is a T5, it'll break once I put some power through it....wish I could be as certain on winning lotto.

crossflow T5 bell and EA to EL will accept any 6cyl T5 box   V8 one has a longer input shaft, so probably could fit with a spacer(if there's enough room for the throwout bearing still, but then it means the tailshaft needs to be shorter if so, i doubt anyone would do that mod unless in a custom car)

picture of the bellhousing area m8,but looks to me just like a normal t5, pre world class are early t5s,easy way to tell 1st gear ratio put it in 1st and turn the shaft by hand ,mark it b4 doing it and 3  1/4 turns is 3.25.1,well thats how i did it with a xg box i put in ryans xe with a 351c and custom bell to suit 6cyl box.

According to goggles that number correspondes with a Non World Class mustang T5....confusing   Pretty sure its to box that'll only take 300lb's of torque...better be gentle with it🤣

Pretty sure the first gear is 3.25, the ute was effortless in smoking the rears in 1st or 2nd and first ran out wayyyy to quick.   I could be wrong but I think the XG longreach had a 3.25 as the first gear...I'd have to find the service manual to check.

I'd have to climb back under the car to take a pic, but i've measured the input shaft and its only 167mm so pretty sure the box is a six cylinder one, maybe the extension housing is from a v8, thats what i took the number from. Its marked 0552-0662903.  Once I clean the rest of the box I'll see what numbers are on the the main housing.   I do know the box has a lot less kays than the rest of the car.   It'll do until my funds start to recover and I can get a TKX in to it😁