Not_so_Evil_Lloyd

Everything from the 80's has questionable behaviour (and i include myself in that statement) If your efe is totally stock atm and you are looking for simple budget friendly upgrades then a GSX600f front wheel will go in standard efe forks with new spacers as its a narrower wheel at the hub. And if you space the discs out (get a machine shop to make one complete spacer up and use longer disk bolts) you can use GSXR slingshot front calipers, they'll bolt straight up to the efe forks. That's what i had on mine at 1st. Then i went to GSXR slingshot yokes with gsxr 1100 forks and wheel re using the slingshot calipers i already had on the bike. The head bearings and stem are a perfect fit just make new steering stops. That was a RWU front end. USD look cool but cost more and you lose a bit of steering lock. Used 1100 fork legs as they are longer. Rear end i'm sure a gsxr slingshot 4.5 rear wheel is fairly straight forward into stock arm. Which would give you a 160 rear tyre. I was always under the impression that 5.5 wheels were too wide for stock arms but i seem to remember someone on here making it work. I just can't for the life of me remember who it was...

Cut it down. Paint it black.

Bandit arm is easier. Which ever swinging arm you decide on you will need to make new upper and lower mounts for the shock and linkage. When i got my efe these had been done but not to a good standard so i used the dimensions and made newer better braced ones. The bike had a GSXR arm in it which was a shit fit. Its slightly narrower than the original arm but not so much more narrow that you would easily get a spacer in. Also the pivot on a gsxr is a solid spindle at 17mm. The Efe is 16mm so yes it'll go through but it'll be sloppy. Mine had a bunch of play because of this. Also GSXR arms do not have a mount for torque arm for rear caliper. Mine had been bodged onto the frame kinda like the GSXR should of been but way too shit I binned that arm in favour of a bandit set up. Bandit arm has a mount for the torque for the brake so that kept it simple. Bandit pivot spindles if i remember right are 25mm with hollow spindle. And the pivot point is narrower. So i made up some top hat spacers that sat inside the bandit pivot bearings sleaving it down to 16mm and also take up the width to the frame. I can't remember the dimensions of them unfortunately but i'm sure someone on here will. Or you'll just have to wait till i get round to my 1100ET project with bandit arm as i think they are the same width at pivot as EFE even though they are twinshock bikes.

Pilion seat and latch is fine. But i don't know if the seats themselves are from the J or the M. What i would point out is by not adapting the grab rail there isnt really anyting behind the seats holding it to the subframe, its worked and survived as its been fibreglassed into a one piece unit. None of this was done by me its how it was when i got the bike. If i was doing it i would say you either need to adapt grab rail as mentioned by @fatblokeonbanditor fibreglass it together like mine. I think its be a bit floppy other wise, and no one wants a floppy one.

My 88 750 has M seat unit fitted. It wasnt done by me it was like that when i got it. They have done away with the grab rail and fibreglassed the panels together on the inside around the light so its all one piece now. With the seats off you can see the frame is narrower than the M frames but it works fine. Mine was converted back when the M was a new bike in the 90s!