forged motor and vvel controller replace

Nissan370

i am being told that because i am having the motor rebuilt
i need new vvel controllers from nissan there 700 a pop and i need 2 of them
what i want to know is can the ones i have be reused

nissan is telling my shop that the vvel must come from them set if the old ones were removed from the heads

and doing any kind of adjustments on them could cause the motor to fail i.e valve to piston contact

i am now hitting 8k and 2.5 months tring to get this dam car back on the road (pissed right now!!!)

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370z vsr motorsports single turbo/built motor 9.1cr 525rwhp/450rwtq @ 10.5psi (stock maf maxed out)