HELP! AU 5-speed accelerating like a pig

[red_devil]

I have an AU2 ute, 5 speed manual, pacemaker extractors, lowered, other than that basically stock.
The thing is, is it accelerates like an absolute pig. Funny thing is, it is as torquey as anything, but I also own an EA 5 speed multipoint wagon which accelerates from a standing start to 100 a lot quicker. Like, one or two seconds. It also required less gear downshifting on hills etc.

I have also owned an auto EL on LPG which was quicker too.
At higher RPM it's not as bad. It's just at low RPM (up to 3500 rpm) its like it's totally bogged down. It's behaving almost like the timing is too far advanced or the leads are stuffed. But, as I have discovered, the ignition timing is not adjustable.

The spark plugs (gapped correctly), oil, oil filter, leads and air filter are all brand new. The inlet manifold bolts were a little loose, but I tightened those but to no avail

Any ideas would be much appreciated. thx