ive seen alum. heads welded but on a 565 alchohal motor and it lasted a lil while but @ 13:1 compression id imagine that would stress an alrady unstable matiral after its welded it could work if metals treated properly i know there only One welder anywere near me who does FLAWLESS alum. welds he makes machines look bad ! let us know how this holds up im intrested to hear