It's a puller type fan, but I don't know what amperage is available to it. Or what amperage it operates at.
I also have no idea of what its CFM rating is.
The link Mike Patterson posted was good (and informative,) reading, as was 'the book' by 36 Sedan, and a host of other comments tended to confirm all this.
So I'm going to have to do a bit of homework on the thing, initially finding out what amperage is available to the fan, find out what amperage the fan utilises (is the motor too small for the job?) what the CFM rating is, and maybe start looking for a Lincoln Mk VIII fan. (Although I doubt I'd find one here in New Zealand!)
I've already cut back when the fan kicks in, it was around the 180 mark; so I cut it back to around 160, figuring if I started it colder it may not rise quite so far.
But that didn't work.
But it was worth a crack.
It's not an urgent must-be-done-tomorrow job, most all of our cruising this summer will be rural to a venue, park up, sit around, drink beer and tell lies with friends.
(Think Coxy and Hippy Mr Spears...they're a laugh a minute. And as you know; there's many more like them out there.)
Then another rural drive home.

So I'll find out what I need to know about the existing set up, then with the information/knowledge/ideas you people have given me work out what I'm going to do about it.
Many thanks for your input; you fellas never cease to amaze me.

And maybe fit an oil cooler too. Every bit helps.