Whatever else you do is obviously going to require some form of fabrication. Depending on the condition/use of your bike, I'd consider welding a lug on the frame for the R5K torque arm. In standard form I would say the 1989 swingarm is indeed stiffer than the 1988.
The 88 swingarm was modified for F3 by welding in 4 gussets around the shock cavity, to strengthen it. (The 89 got a new swingarm with enlarged cast section.)
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Andy.
NSR-WORLD.COM
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