I am running stock head castings and upgrading the valve size to 2.02/1.60. My hydraulic roller cam will have .570 lift with the 1.6 roller rockers and I shouldn't be running more than 15-18psi. I figure I'll be shifting around 6300RPM since the cam stops making power around 6000RPM.

It seems that I am going to need to have the heads machined to fit a bigger diameter spring but what do you guys recommend?
I can not get ahold of comp cams but I talked to an engineer at Erson Cams and he said I need something with about 150-170 # seat force and in the low 400 # range open force.
Also will a stock type lifter support valve springs as stiff as this?

 

I am curious as to what springs people will recommend for you. You may want to check out a set of trick flow heads though. I had similar plans to yourself until I found that it may be cheaper to buy a set of TFS's with the larger valves. They also sell a set that come with 62cc chambers to drop compression a little more as well.

http://web.camaross.com/forums/showthread.php?t=505062

Just food for thought.

 

Yeah, I considered new heads but there are some places you have to make budget decisions and that was one of them.
I've spent ALOT of hours working the stock heads and trying to open up the chambers to atleast 58cc. I'm worried about taking too much out of the chambers because its kind of hard to tell where the water passages are.
My pistons are -26cc JE and I plan on using the Felpro head gasket.
I need to go measure my deck height but if I use a value of 0, my CR is about 9:1 with 57cc chambers. Right now my chambers are a little better than 57cc if my measurements are accurate.

Anyways...I finally got ahold of CompCams
Their recommendation:
Machine the heads for a 1.445 or 1.450 diameter spring
Use a .050" keeper
26120-16 Spring
795-16 Retainer

He talked fast but I think he said 1.880 installed height should net me 155# on the seat and 377# OPEN @1.280.