AIRBOX MOD 91-750

[old zx750]

I'm in the process of doing some mods to my 91-zx750, just pulled the tank and airbox/carbs what a design! can't remove air filter without carbs and air box , the cool air tubes run through the tank and cool air over airbox , air inlet horizontal at back of box so I plan to cut a couple of holes vertical above standard inlet.
pulled rear shock -stuffed and have a 09 zx9 I think, shock that should work i'll post pics -heaps more comp/rebound adj
weighed 03 gxr rear wheel 3kg lighter with a 190 tyre ,i'll check sprocket/ front wheel alignment tomorrow
going to weigh a 01gsxr front wheel also and disc/caliper fitment
replace the stock muffler with a straight through Yoshi ,any ideas on how much to jet up ?

[old zx750]

Shock is about 30mm shorter,canister would hit batt box, make a bracket 30mm longer retain rear height adjustability
10 adjustments on comp/rebound easily assessable

[old zx750]

03 v 91 wheel

[old zx750]

raised srad gsxr handlebars -going under top triple clamp

[old zx750]

01-03 front wheel

[old zx750]

stock muffler v Yoshi alum

[old zx750]

inlet showing horizontal inlet ,is there supposed to be a forward facing piece that goes on back of air box ?