Best budget valve springs for a mild 351w?

[Stangman]

I'm no expert when trying to figure out what valve springs are needed for an engine... Can anyone help me?

Here's what we have:

'91 351w currently stock bottem end. Changing out dished pistons for flattop hypereutectic pistons with valve reliefs soon.

GT40 cast iron explorer heads (not P's) which will be milled at the very least 10 thousandths of an inch to help with compression and clean up the bottom ( would like to go a full 30 thousandths but I think that may be too much). Drilled head bolt holes to fit 351 head bolts.

An older Comp Cams hydraulic flat tappet cam, with specs of 512 lift, and 292 degrees of duration. I'm not sure about anything else on the cam.

Edelbrock Torker II intake manifold.

720cfm Road Demon carb with vacuum secondaries (which I'm not wanting to use, since car is a 5 speed)

Would like to find some decent/cheap 1.6 roller rockers that are pedistal mount to use in the future.

So, With all this info... can Anyone tell me what valve springs we would need? Or anything else recommended for that matter...

Thanks

[Walter]

http://www.summitracing.com/parts/EDL-5722/

http://www.edelbrock.com/automotive_new/mc/valvetrain/springs_retainers.shtml

[Stangman]

Is there a reason that the spring diameter is larger on a 351? And if we are putting 302 heads on it, would we still need the larger diameter springs? Would the seats be different?

[Walter]

Meh, I think the exhuast valve groove is lower on the gt40's. Not sure. Disreguard my previous post.