WELCOME purefun660. We're glad to have you join us. You will get tons on advice, mostly good from fellow Stovebolters. Many are very experienced hands at getting the best performance from stock and non stock inlines. You may also want to check out
www.Inliners.org for some help. Hopefully we'll see you here often too.
As for the machine shop I wouldn't be as concerned about any of the last generation of Chevy straight sixes as many would lead you to believe. They have much more in common with more modern engines than the older tapered cranks and poured bearings of earlier models. Your concerns are more from a holdover from those days than a 230,250 or 292 warrants. Just take the same precautions you would for any machine work, i.e., ask questions, get firm prices and references. And if a place is dirty and looks like trash then thats what the work will be too. Check out the NAPA stores in you area.