C4 suspension forgings

[pacificstudios]

I’m building a ’66 Corvair with a fabricated “backbone” style chassis for mid-engine placement and greater stiffness. For the suspension I’ve acquired two sets of C-4 Corvette forged aluminum front suspension pieces that will be used at the front and rear (a la Shelby Series 1). The lower control arms have a boss located on their leading and trailing edges that receive fasteners for a stamped shock mount bracket in the stock configuration. In my application, a bracket will be fastened to the “floor” of the control arm to receive the bottom mount of a coil-over shock thus obviating the bosses. I'd like to grind off the bosses to get rid of all that ugly, but one half of the blind threaded hole in each boss would remain on either edge of the control arm. The question is; if I want to weld up the remaining "half holes", what procedure must be employed for welding a forging of this nature without ruining its inherent strength? If it is acceptable to weld it, should the same alloy as the control arms be used as the filler? How do I find out what alloy the ‘vette control arms are made of? Thank you.