new summit performance vortec heads wondering about springs

New to building engines. Just bought some new performance vortec heads from summit also bought a xtream energy cam from comp cam and it calls for a part number spring of 981-16 but i was wondering if the springs that came on the heads would work fine. The springs that it calls for are set at 105 lbs closed and 273 lbs open and the ones that came on the heads are rated at 110lb closed and they are rated at about a .525 lift but no one could tell me what the open lbs are. Could anyone tell me what they are rated at or how to go about finding out. keep in mind they are they summit performance vortec heads not the stock. thanks for reading.

ray  

To be safe with any purchased complete head assembly, you need to take the cam specs to your machinist and let them pull the springs and check them for installed height, coil bind and full open load.  Most of the aftermaket bargain heads come with the cheapest springs that can be found, so replacing the springs on new heads is very common, especially Edlebrocks.  On the other hand, if the springs meet the specs for the cam, then run 'em.  But get them checked.

New to engine building, well here's the best advice I can give - NEVER assume ANYTHING.  CHECK it all - everything, then check it again.  And check it RIGHT NOW, while you can still get it fixed - not 6 months from now when you decide to use the part.  Example - I'm building a new 351C, running high buck Probe pistons.  Never had a problem with piston ring fit on a piston, ever.  So - I never bothered to check the ring lands.  Probe cut the oil ring lands wrong, so now I have a set of $500 balanced and massaged pistons that will require another $120 spent before they can go in the engine.  CHECK EVERYTHING, as soon as you get your hands on it.  

Like Falcon said, you'd better just check to be sure.  Typically a spring like that is going to be pretty close to 300# open and that is about the max you want to have if you are running stamped steel rocker arms.  I'd really consider a roller trunion rocker.  

thanks for the info i was also told that i could just go to a local machine shop and they could tell me what it is at at 1.7 in like i said the cam calls for a 105 open and a 273 open. thanks for the help

ray