vacume pumps on blown alchole engines

morning guys,

what before / after experience have you had, with performance, and engine maintance , with racing without a vacume pump, then fitting a vacume pump ?

or

at what stage , do blown alcohole engines require them?


running a twin turbo mfi sbc, @ 36+ psi.
Tune up is pretty good, engine oil does 7-10 runs before change.

Thanks
Ash