Hello
I'm planning to use the pictured valve springs on the Vortec heads on my factory roller 350 Chevy engine, together with the GM HOT cam and 1.6:1 rocker arms.

GM HOT cam specs:
.525 LIFT WITH 1.6 ROCKER ARMS
.218 DURATION @.050 INTAKE
.228 DURATION @.050 EXHAUST
112 LOBE CENTERLINE

1. Do I have to change to screw in rocker arm studs?
2. Should I use full roller rocker arms?

 

Those springs installed at 1.750 will beat the crap out of the valve seals with .525 lift.

Stock Vortec heads won't take more than .460 lift.

 

1. No, you do not need screw-in studs
2. Should you.....yes. Must you.....no. If you used slotted stamped rockers, just make sure the slots are long enough to accommodate the .525" lift


If you got the complete kit from Alex's, the modified retainers will permit up to .550" lift without seal-retainer contact. If you didn't, do the "ghetto grind" to the bottom of the retainers and run 1.5 rockers instead of 1.6.
IMO, 110 lbs seat isn't enough to run the Hotcam with stock Vortec valves (as opposed to the lightweight LT4 valves), certainly not with 1.6 rockers. I'd shim them to get 120 on the seat. The better kit would have been this one:
http://www.alexsparts.com/valve-spri...rf-hyd-roller/

 

Thanks for your answer.
I have bought the kit, and this is what he recommended for my set up.

 

You'll be good. He probably just doesn't know the rpm capability of that cam as well as some of us do.
Just shim them to a 1.700" installed height instead of the reference 1.750". Even if you can't, it's not a deal-breaker; run 1.5 rockers and limit your rpm to 6000 and you'll be fine.