I got a quote for cleaning, magnuflux, milled surface, 3angle valve job, bowl blend, valve guides cut to except higher lift, reassembled with new z28 springs, seals. When I mentioned brass valve guides they said theres no need(without seeing the heads) if anything theyll put in factory cast iron inserts, he also said no porting or polishing included. I was told $600. Is this high?

 

Yes I think so, and I wouldn't put iron guides into an aluminum head - ask for bronze.
I wouldn't get any more quotes from the shop without them seeing exactly what you've got.
Also get part numbers for the springs and seals they would plan to use so you can check the specs yourself.

 

If he is charging you to magnaflux an aluminum head he is ripping you off. "Z28" springs probably arent the right springs for your application. He is going to stick some crappy 50 dollar valve springs and charge you more for them because they are"z28" springs.

 

There is alot wrong with your statements fom this guy.
first and most importany to give any estimate the heads must be looked at!
heads need to be part of the total package spring match the cam period.
aluminum gets solid brass/bronze valve guids period, cast iron and brass inserts go in iron heads. port work is done b4 valve jobs,...ect,ect
way over pricewd for the wrong work.....get a better shop to do them!!!!
the person doing the heads should first listen to what your going to do with them and set them up accodingly....also have them back cut the valves.