I had one of these on my ABF for a few months, it did fit.
One of big issues was how it fits onto the CAT -the manifold uses a ring & the CAT has a flange -its also a smaller bore than original.
The other issue was the lack of flexi connection, I have hockey pucked the front mount and had a new gearbox mount fitted -despite the engine hardly moving around it kept snapping bolts at the down pipe to the CAT. didnt have the time to look at it properly, took it to a local tyre tyre depot, they put even larger bolts on than standard, everything was good for a week until I down changed and the manifold snapped at the collector.
Reverted back to original manifold, much smoother easier to rev, it has a flexi connection & more power - not had a problem of bolts snapping since.
I suspect these are actually a Mk2 16v manifolds