What Can You Tell Me About These Chevy Heads??

I need some info from some of you Chevy guys. The heads I have on the '99 350 Chevy engine I will be using for the T are Vortecs, and have the following part number stamped on them. This is what I pulled up from Mortec:


10239906...96-up...350.........."Vortec 5700", "L31", 64cc chamber,
170cc intake port, 1.94"/1.5" valves

I know these aren't super high performance heads, the Volvo marine engine they came off of is rated at 280 HP, but i would just like to know a little more about them, such as are they pretty fair heads or dogs. Also, can I go to a little hotter cam with the stock springs, etc.

Thanks for any info you can give me.


Don