I found that I *really* liked the way my '89 cornered after dropping the front end 1/2" or so down the fork tubes.
A lot of us have also raised the rear ride height, either with different shock linkage "dog bone" links
All of Bill's suggestions and advice are excellent but the two points he makes above never seem to get the credit they deserve for the difference they make. I've got the flashy shocker, forks, wheels, tyres, brakes, hoses etc but it was finding the sweet spot on those two things that transformed the handling, the feel though the bars was perfect, I didn't even bother with expensive fork brace I'd just bought (although I don't think anyone else here shares that view).
I also have a bog standard FJ which rarely leaves the shed but when it does or when I ride someone else's bike, the first few corners until I get used to it are a bit hairy, it feels like it doesn't want to turn in, cornering is hard work by comparison and a line not as easy to keep sharp.
It's easy to forget in this forum wonderland of mods and Randy's lolly shop that a standard FJ even with only a half decent shocker is still a very rideable bike.
A good rider can ride around most of the FJ's shortcomings, the improvements just make it easier.
I have a modern bike with handling by God. It has wishbone suspension, electronic pre-load adj front and rear, on the fly electronic compression and rebound adj, 320 mm boosted Brembos, auto stability control, traction control, ABS, similar power and more torque than the FJ, same tyres, linked brakes, same weight, more clearance etc. As you might expect with all that electronic wizardry and modern technology, it is a better handling bike than my FJ -
BUT NOT BY MUCH!!!I have always maintained the FJ is not a good bike for it's age but a good bike even by modern standards (with a few mods done). The same could not be said of all the "classics" from the same era.
I've put over 220,000 km on mine in 11 years, every one of them out in the country, I don't commute. The list of components that are still original speaks well of the quality back in the day and a great mechanic to maintain it. I love it and finding a modern stable mate for it was not easy. As it is, I still do more miles on the FJ.
They are a truly great bike and every mod you do will only make it better.
Enjoy
Noel