Marcos Maniacs

Are there any adjustable GT-6, Spirfire control arms?  From the 
factory, GT-6 and Spitfire  lower arms could be "shimmed" for caster 
and camber.  On my Marcos, #8001, the upper and lower suspension 
pivots are welded to the chassis.  Has anyone modified their chassis 
to adjust caster and camber?  Perhaps cutting the inner lower control 
arm brackets off and installing the stock inner lower GT-6, Spitfire 
pivots.  A tube would have to be welded inside the frame for 
the "cross bolt" that takes the shim, maybe double the thickness of 
the frame tube in that area.   Are there adjustable arms out there?  
Has anyone on the list modified their chassis to adjust front camber 
and caster?  My experience has been, that a good wheel alignment 
transforms the handling of most cars and is well worth the time.
                        Thanks, Steve Vukobratovich
                                Sierra Vista, Arizona