will this fit?

Will a 130 90 rear tire fit a stock 75 z rim and have enough clearance for everything? It seems to be about an inch wider than stock

yes

I have 130 tyre on stock z1/kz900 rim and it fits without any problem.

I"ve got a 150-80-16 on my '77 by using a stock 1981 LTD swingarm.

L, clearance is seldom problem.as wider tires are designed for wider rims. putting a wide tire on a narrow rim results in a skinny tire with a peaky profile. whn gone to extreem. looks like a bald mans head, with decreased footprint at sides just where you need it most. depending on tire, 130's are usually fine. look at the shape of tire inflated on rim. measure width of say stock 400/425 as opposed to 120/30/40 and you'll see what I mean. luck g

at a truck stop a guy had a z-1r in the back of a truck.....
i walked over and was looking at it....he had a 160 on the back...so i asked him how he did it....he said "they fit ,try it"... i thought about it for a few months....later i asked a guy who knew bikes for a job and he said what gane just stated ...and said not to ever do that or you are asking to have a slide out or highside....that was good enough for me ...the rim dictates the tires abilty to spread to it's designed shape....hmmmmmmmmmmmmmm