As far as I've read Ron you are correct. It was just a better second gear added. I acquired a motor that turned out to be DPort which came with a 4 speed gearbox. So I'm intrigued what it could be.

Hi Keith, regarding the original question just mark the input shaft and the output shaft with some white paint so it can be seen how far they turn. Then find second gear and turn the input shaft so that the output shaft makes exactly one turn. Then note how far the input shaft has turned. Early box should be 2.214 turns, uprated box should be 1.942 turns.

Correct Ron: You stole my thunder !

Yep that is the only way to truly know. It's not in a car so should be easier. Only hoping but I'm sure it's a standard V6 4 speed. Cheers all.

Wiggy,
 
The earlier versions have the breather in the extension housing where as the later version! has the breather at the front of the main box body.  I have seen the later versions with both ratio sets but the majority have been the later gear sets.
 
Regards
John

So were many cars built that had the external link gearbox and the upgraded 2nd gear or was it only on the 165HP specials?
 
To convert a external link gearbox, is it just a matter of changing the cluster and 2nd gear over from a type 5 gearbox?

Ford supplied the "uprated" gearbox to the 11 165hp cars.  I assume there were some extra ones around for warranty etc.  I am in the process of having the gear set in a regular side link box swapped for type 5 internals, so as to return my car to its original 165hp running gear.  My understanding is that you need the matching idler (?) gear as well as the first / second cluster to match gear teeth pitch

So I've counted it out and I'm getting 2.5 revs of input to one rev of output. It's certainly more than 2.2 turns. The breather is on the front square box. It has a metal tag which I'll try and clean to read the info.

Can someone point me in the right direction of finding second gear on these gearboxes. Sounds stupid I know but I'm getting old. I tried to do the same on an early version box that was working on removal and could not do it. My process is that the lever toward bell housing is 3 and 4 with neutral in the middle of that selecter. Second toward rear does 1 and second with first toward rear and second toward bell housing with 3and 4th lever in neutral position and the third lever is for reverse which points down not up. I tried this with the other box today and could not select gears this way. Are the two boxes different. One has breather in the tail my old box the other has the breather in the front near bellhousing on the box section. The one with breather on box section selects gears as above the one with breather at rear stumped me today.

Wiggy,
Rear Lever vertically up, neutral in middle, forward is 2nd and rearward is 1st.
Front Lever vertically up, neutral in middle, forward is 4th, rearward is 3rd.
Lever vertically down at rear, neutral rearward, reverse forward.
 
Hope this assists.
 
Regards
John