The issue you have or may have is with the head being skimmed it will put your cam timing out, you could run a venier put needs setting up on a rolling road really.
Thanks Wayne will do !
Was it skimmed to remove warping or skimmed to increase CR?
If it was skimmed to remove warping then this should be within manufacturing tolerances and should not affect cam/ECU timing unless it was realy bad and should have been binned anyway.
If it was skimmed to increase CR then it would be worth trying a remap
to re time the igniton cycle.
If you overskim a head you can get a diesel effect where it combusts/semicombusts before true detonation (which can shag your engine good).
This could be why the engine revs freely but under load does not develop the power you expect.
Was the gasket thickness calculated on the skim or just guessed?
On carb engines it is easier to skim heads for peformance purposes and to deck the block for even CR but with modern engine management systems it is not as easy to set up by re timing the engine mechanicaly.
As Wayne said you could try a vernier but you would need to check the map and adjust accordingly on a RR
Best to fit a cam and do all the work in one hit.
I would check the cyl compression to see if you have edged or bent a valve through over skimming before you fork out any more money.
When you say the head was ported was it just matched to the gaskets and manifolds or was the CC area flowed it can be a fine line between turbulent and laminar flow on the inlet and outlet that make or break a head, ive stuffed enough Escort heads up working out texture and polish paterns

IMO MK2/3 8v difference is in the handling not straight line times.
More torque helps MK3 with weight but dont help the roly poly in the corners
