My main recommendation would be to stick with the stock sizes, oversized tyres mess with the handling.
Aye sfb,
I cannot emphasise enough the importance of Steve's comment above and his recommendation that you check the tyre sizes for the earlier twin shock model.
A 110/80 H17 on the front of 'Sally' SRX600 1986 (had the 1987 3 spoke alloy wheels fitted from a SRX400), made her roll like a drunken sailor on shore leave, on banding, tar joints, linear abraded surfaces and worst of all, the tramlines/ditches/canals created on worn out roads by 'Super-single' lorry wheels.
Re-fitting a standard 100/80 H17 made a completely confidence inspiring front end return. No weave or wander and rapid steering.

Check your pressures every time you go out, a couple of points out in Bars or psi will make all the difference.
'Super-singles' is a rant subject in my opinion and I need the shut eye tonight!

So will say no more.
All the best, Bill.