i just had my 304 fully rebuilt...new cams ,new cam kit, timing chain etc pistons ,rings 2nd hand rods as one of mine was bent.. rebore etc etc new radiator as mine was toast ..your not going to do a rebuild with a crap radiator i had electric fans added plus all the gaskets fluids labour...not much change out of $8K............your not going to get anyone to do anything if you ask them you just want this or that done to it as most mechanics dont want to go down that road for good reason.....i just told the guy do a rebuild and replace what is needed.......i went with a stock rebuild as i can loose my license easy enough with a stock 304..........................job done at Nowra
https://www.horsepowergarage.com.au/