KZ440 which rear shocks

Hi

What's the go-to replacement these days for rear shocks on old Kawasakis please? I've got a KZ440, and I've got the front dialled in exactly how I want it, with a bit of additional preload and heavier fork oil. Works nicely.  However, the rear shocks are the weakest link, and the bike is like a pogo stick if it hits a slight bump (not even a pothole, just a bit of tree root pushing up the tarmac) at speed. It will corner though. The rear shocks are (I believe) original Kawasaki, and they're very basic with no adjustability except for preload. At the moment it's on the zero preload setting. I don't really know if they would start working better with more preload or whether the problem is rebound damping causing a bottleneck restriction with sudden impacts, or packing or whatever. I think it may be a nicer experience all around with modern shocks. 

Thanks

I would check Hagon and Ikon. Some folks like Progressive shocks, but I am not one of them.

I am using a set of Ikon 7610 1539SP8

I put them on about 15 years ago so I don't remember for sure but I think they came with the wrong bushings because I intended to install these on my Ironhead Sportster. I think I adapted something to make them fit, i don't remember what. But you can order the correct bushings for them. According to Ikon. the correct shock for our kz440 is their part# 7610 1348SP8 and that "correct" shock is 20 CM longer than mine which you see above and they come with the correct bushings for the kz440. If you like the look of the extra long OEM shocks then get the recomended part# 7610 1348SP8. If you like the look of mine then get part# 7610 1539SP8 and also order the correct bushings to make them fit our bikes, the part number of the correct bushings is 70 52 11 367 0 (you need 4 of them, 2 for each shock). 

Do not get emgo shocks. one size fits all is a bad idea and those are too stiff for a 650, so they'll be like struts on a smaller model.

YSS shocks

www.suspension-store.com/YSS_Kawasaki_Z_440_80-84_KZ440A
www.yss.co.th/products/list?vehicleTypes...odel=18926&year=1984

YSS-RE302-330T-25-88
YSS-RZ362-330TRL-25-88