Dave, I've followed your journey with some interest as I started something similar with my old 4/4. Firstly tuning the 1800 Silvertop Zetec and latterly transplanting a 2.0L Blacktop Zetec. (before I was seduced by the Roadster) Bear with the initial descriptive stuff because you may not have seen my older posts a few years back.

I used a basic Omex ECU which didn't have much in the way of real time data-logging so I did most of my development work on a friendly local dyno.

While I was playing with the 1800, I went through a few stages. Firstly I ripped out the original ECU and wiring and put in the Omex together with removing the Morgan intake and MAF meter but retaining the standard Ford plastic inlet manifold and throttle body. Aluminium on the old silvertop if I recall.

I also fitted the Librands manifold and exhaust system but retained the standard (400 cell ?) cat.

Can't remember the numbers but I do remember being very pleased with the initial dyno set up and runs which prompted me to carry on the tuning so I had some very mild head work done (standard valves) and fitted a fast road cam (Kent).

Went back to the dyno and played about with the mixture and ignition mapping and was hugely disappointed. Very little gain in horsepower and a horribly lumpy torque curve.

Dyno mans first thought was let's alter the cam timing a bit because the standard settings for the new cams might need tweaking to suit this set up. However, I had not fitted vernier cam pulleys so we couldn't play any more.

So abort that session and go home to fit some vernier cam timing pulleys and then back a few days later to play with the cam timing

We played about by advancing and retarding the cam timings and in the end we did get better results both in peak horsepower and a smoother torque curve but still nowhere near what I expected.

He felt that the problem was that the cams were trying to produce peak hp at 7000 rpm but the manifold was tuned for the standard cams at about 6000 IIRC and so they were in effect fighting each other.

I didn't want to start playing with throttle bodies and in any case I had a brand new 2.0L crate engine sitting in the garage so I stopped the 1800 work and dropped the 2.0L in using the standard inlet manifold and throttle body and the same Librands exhaust and Omex set up from the 1800.

After running the engine in for a few miles I went back to the dyno, tweaked the fuel and ignition mapping and we got 160hp @ 5920 and 157lbsft @ 4420 rpm. But as I said earlier I was then seduced by the Roadster

Anyway, when I saw your dyno run it brought a few thoughts to mind.

I don't think you are getting wheel spin at 6500 rpm because that's well past where peak torque is occurring and assuming this was a 4th gear dyno run the transmitted torque to the rollers shouldn't over power the traction with the 2.0 litre engine unless the drum was very slippery. (Usual caveat. I could be totally wrong)

When you are happy with the fuel and ignition mapping, I would be tempted to look at the cam timing and adjust it a bit to see if you have got the Newman cam optimised for your engine set up. A few degrees advance or retard could make a significant difference.

It might also be worth considering if the length of your intake runners are in tune with the cam profile. IIRC you have fairly long runners on the inlet which should give good low down torque but are the pulse timings matching the camshaft inlet timings. Just a thought.

Seeing what you're doing with Monty sort of makes me wish I still had my 4/4 2.0L Zetec to play with.