I have to agree with Jack that Culnacuries is by far the best contender for Gualnacarrie in areas that might have been associated with Muthill.  The exact view on the NLS website is:
https://maps.nls.uk/view/74400315
and I attach an extract from it.  On the extract, Comrie is towards the right hand side near the top.  Follow the Ruchill Water south west from Comrie until it goes across the join in the map, and Culnacuries is just below the river at that point.  The only named place in that vicinity that is still shown on the 1866 OS map is Auchinner, a short distance to the west of Culnacuries.

Well found, Jack.  I was too hung up on finding an Ordnance Survey map and did not look in the Counties of Scotland category in the map series dropdown menu.

John

Ken,
This is a rather wild guess, so very possibly wrong.
There is a similar name to Gualnacarrie.

It looks to be a farmstead - Culnacuries.
And is SW of Comrie village.
(in part of Strowan Parish 1783) (Monzievaird & Strowan 1805)
It's quite near the parish borders of both Comrie and Muthill.
But the name seems to have disappeared by the 1860s.

https://maps.nls.uk/
(The Counties of Perth and Clackmannan. Jas. Stobbie 1783 / 1805)

Jack

Virus-free. www.avast.com