The heads I purchased came with sring specs as follows.

135 lbs Seat pressure at 1.800 (+.1" valves)
320 open pressure .600 Max Lift
Screw in studs

I am bolting these heads on to my existing mild hyd. cammed 327 (mild as in slightly above stock, runs to about 5200 before falling flat)

I will be running the $100 Comp Cams pushrods, and Pro Magnum Roller Rockers. Should I be concerned about too high of a spring rate, or is everything fine?

I can't answer your question but will mention that the cheap Manton springs Part # 2454 I got from Competition Products for my BB are spec'ed like yours. (I'm not worried about rpm'ming my big engine so they are fine)..

I opted for a set of their .050" taller keepers/locks b/c I was worried about too much seat pressure on break-in..

Please consider this suggestion and to tell you how much it drops the seat pressure you just need to calculate, (if you don't have it already), the spring rate and take it by .050" and subtract it from the seat pressure if I am not off here??

It's been a while since I did this to check springs... pdq67

PS., calculate the spring rate by this!

Open pressure-seat pressure/seat height-open height

Measure the actual spring heigh as set in the heads.
Springs should be one of the last peices you buy, as your putting your heads together.
I learned that you first set up the heads, check the spring height, then choose a set of springs.

These are out of the box Pro-Topline heads that came already assembled as specd above so that I can run a future engine with a hefty solid cam. I guess in general what I'm asking is what are the dangers in running a higher spring rate?

Build the engine that you WANT, right NOW. Dont build it with a future combo in mind, build what you want to build and stick to it.

I see alot of people screw up there combos becuase they pick heads for a big inch combo down the road, ect.

Another thing i would do is not buy the heads already assembled, instead have them bowl ported and prepped by a reputable machinist.

Back again, I forgot to mention that the .050" taller keepers/locks dropped the seat pressure down to just about 123 or so which to me will help break-in, but still not hurt my self imposed rpm limit of around 55 to 5700 rpm or so up top!! pdq67

That's a good idea PDQ - installing +.050 keepers to drop the seat pressure . . . would have never thought of that. graemlins/thumbsup.gif

A little extra spring pressure is no big deal if you are using a cam that is already broke in. BUT if it is a new FT cam you had better talk to the MFR to see whether your springs are OK or not. It's easy to flatten a lobe on break in with too much seat pressure.