With an open budget I would probably get an RB C6 turbo or an OS Speed.. Slightly less expensive, I would get the Orion CRF 21.. - the most impressive engine probably that I've actually seen live.. It's silly powerful... Next down in budget, one of the other Picco-based 21's.. Then I guess a VSPEC or Sirio..
(But to be honest I'm expensive-motor-shy and might just go back to my good ole' Mach 427..
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