I bought my 1991 +8 some 6 years ago, it has the Jack Knight Rack & Pinion.
The first (for me) MOT threw up a split in the gaitor which needed to be replaced, this filled me with dread but Lorne Goldman's invaluable GoMoG Manual laid all before me - Link
HereI then had two shocks one after the other !
1 - The price, over £60 +VAT from the Dealer.
2 - The quality, this part is in my opinion the worst piece of cr@p sold by Morgan and that's saying something.
Following the GoMoG instructions was straightforward and it was all sorted in no time. 12 months later, the MOT threw up - a split in the gaitor and a repeat performance under the front end and again 18 months after that. I looked around for a 2nd hand Quaife Rack & Pinion without success, the price of a new one proved too steep as well, and I searched for an alternative gaitor even buying one or two to test, still no luck. Then last year I noticed Uncle Melvyn had a couple of used (3000 miles) items, a few hundred pounds and at last I had a Quaife unit with proper gaitors. Just a week later I found a TM Thread
Here which took me to Simon at SiFab who sells a replacement 'kit' using a quality SAAB gaitor and a couple of small adapters, half the price of Morgan too

arrived in double quick time (Thanks Simon).
I've yet to decide whether to fit Simon's Jack Knight gaitor and carry on or switch to the Quaife which apparently came from a LHD conversion, other Dealers may have one so ring round if you're interested in such a swop.
I have no axe to grind but thought I'd post my experiences.
Have Fun

Andy