Maximum lift?

well if you:

"PS if you are after a little more HP and going with new valves, then when you get the guides go with the 11/32 guides and slimer 11/32 valves(chevy type). This is only if you are putting a lot of $$$s in the heads"

So if you go with performance 2.02 intake 1.625 ex. then do seats, port work etc. you might be about up to the same cost as you would spend for Edlebrock heads?

For me I have access to a machine shop and 30+ years of experiance so I was able to save the labor but I still spent about $600 on my heads not counting springs, retainers and locks. I am close to a grand. Even so I wanted to see how she will run, some day I may go aftermarket on the heads.

But you need to figure out what the cost for the heads work and how much you want out of the engine?

Back to your last question, yes with some decent port and bowl work from a person that know what they are doing you can gain a decent amount. Then you nee to make sure cam, intake, exhaust etc are all matched for the work performed and determine what RPM level it is best suited for?

On the street it may hurt your low end 2-4k rpm levels some, so just a heads up.