Kevern. You have two choices. Chop off the front and rear sections and weld on new frame sections Or buy a complete new chassis. Chassis sections from Mick Sollis at Southern GT (
Southern GT - Manufacturer of the new Southern GT40 Replica-4fe109c5eb93f0f4e057a9ccf335121b). Complete chassis from Southern GT, MDA or Tornado for spaceframe types. Check out the build section for info and pics. Question: Do you want an integral rollcage?
If you want alloy uprights and peg drive hubs they are expensive but very nice to have (from John Wisher in UK). If you want some steel improved uprights for 5 bolt wheels rather than the Ford Granada items contact Mick sollis at Southern GT.
As you say the KVA bodywork is good (and fits well). I have some pics of a late type KVA which is being built local to me.
Final Question: Do you want a rod type gearchange?
Cheers
Mike