When does the stock head benefit from upgrading. I'm going with a 83.5mm or 84mm bore size. Would I gain that much from matching the bore size to the head. Also if you're only rev'ing to stock capabilities what gains do you get from stock sized aftermarket valves. Why even upgrade to better springs and retainers?

 

You benefit from upgraded springs and retainers when you plan to raise the rev limit. To avoid valve float. As far as aftermarket valves, I dunno. If you were going to go that route, I would do a full valve job, and have a experienced head porter work on the valve seats. An experienced head guy i know said that the first part of working a head starts at the valve seat, and then you work from there.
How much power are you looking to build for?

 

I dont really have a HP goal right now I just wanted to make sure that there wasnt any unforseen problem with running a fully built block with a relativly stock head (b16 head, w/ gsr cams).