Hi Seanick. If you're worried about axle tuck induced oversteer there are several ways you can alleviate those symptoms:
A number of Spyder builders have converted their Herald/Vitesse rear end to the Spitfire IV/1500 swing spring set-up;
Using a Spitfire IV or 1500 as a Cordite donor will give you the swing-spring back end as standard anyway;
A Mk2 Vitesse donor will come with double-jointed Rotoflex rear driveshafts;
Or, like mine, lowering a swing-axle Herald or Vitesse by around 90mm means that under hard cornering when the weight comes off one side the wheel reaches the end of its travel before it gets anywhere near tucking under. In the pic below I've jacked up one side but
both wheels are off the ground
Anyway, if you're the kind of guy who enjoys building/driving an Arrow I'm sure the Sammio bug will bite soon...
Oh, and just noticed that in this picture it's kind of simulating a hard left corner where the off-side wheel would actually be under full load rather than dangling as it is but the attitude of the nearside wheel is critical as that's the one that would be in danger of tucking under, and, as you can see, it's almost vertical to the ground at full extension so no tuck under.