I purchased a gen3 head a long time ago and I'm just getting it on now. I went and bought new valve cover gaskets for the gen3 mr2/st205 only to find now they are wrong. (11213-88480 and 11214-88480)
So I now presume it is a caldina head but the every picture i look at and also parts diagrams on toyodiy I cannot work out what this valve cover is from. Both ST215 and ST246 look different.
 
Did the gen3 3sgte come out in any other cars? (dont worry it will get a good clean up and pait before i use it.)

 

This looks identical to the valve cover of a Gen 3 3SGE.  

Yeah its slightly different to a gen3 turbo

so a 3sge valve cover will bolt up to a 3sgte head? it's the turbo head for sure.

It should bolt up fine. The only issue I could see; would be that with the raised part of the valve cover might foul the bottom of the intake manifold. Dont take my word for it though...

Yeah it should bolt up, but it dose not have the cut out for the manifold bracket to bolt through and clearance might be a issue
This is a gen3 turbo
 

i have a side feed intake so that wont be a problem. Now I'm thinking what if I've got a 3sge head?
I presumed it was a gte as it had a turbo off the side. but maybe its a worked 3sge head,
it has oversize valves than gte and bigger cams also. 
Are there any main differences I should be worried about?
It had a turbo intake manifold bolted to it to so I just assumed. But I guess now maybe everything is interchangeable?

the basic bare head is all the same.
 
did it come with the top or side feed injector rail?
 
NA cams is a bonus, but it may have aftermarket stuff anyway sounds like?

yeah its been worked, ported, valves, 264 and 272 cams, and hks rail. 
Looks like everything will work out fine. The water connection on the rear seems to be the only difference with the mr2 i think

Water connection on the rear? Of the coolant neck, or do you mean the drain for the oem blowby catch can on the back of the head?