my best advice with riv nuts is always use the steel versions, the ali ones shear too easy......ref IRS conversion, see this link, you will not find a better explanation of how to do it.......be warned, its major surgery, and lots of new components, and will add about another 20Kg to your fug - not good
http://www.blindchickenracing.com/How_to/I...Sconversion.htmNow when I was looking for a Fug I wanted an IRS rear........but this fug-4 came along with swing axle, so decided to give it a go......and I must admit there is no problem with swing axle in a fug, heres why........in a beetle it could be argued that IRS is a must for a good street handling beetle.......as the centre of gravity is so high, the body mass rolls tha chassis more, hence the tyres need to be kept in contact with the road better........IRS is good for this.........BUT.....as a fugitive has such a low centre of gravity you get next to no body roll, hence no requirement for IRS........I have literally thrown my swing axle fug-4 around roundabouts exploring its limits, and I can assure you its quite OK.
Also formula Vee racers use swing axles, and they do 53 second laps around brands, hatch indy circuit, the same as formula ford 1600 lap times.......rest assured, swing axle is quite OK for hard fugitive street use.
you will notice more difference by playing with your ride heights, lower profile tyres, bump stops and spring stiffness.