I had a 1981 Z750E for 10 years. It was sold to me after 3 previous owners had flogged it mercilessly at the drags (as a learner drag bike.....) for the previous 10 years. I re-ringed it, put on slingshots off a oil/air GSXR750, milled the head into the valve seats
, then proceeded to flog it myself everywhere for the said 10 years, until finally 60000km later one of the rings broke, dammit!
So I re-ringed it, cut up a swingarm off a ZX9 and solid mounted the thing with 3=point linkage arms from the shed, modded the slingshots for methanol, and now it's doing consistent hi-11's with my gleeful son-in-law giggling all the way down the track.
Still love that big ugly POS!