Question about springs for vortec heads

[67ss&99ss]

If I use these springs, gm part #12495494 will I have to do any machine work to my vortec heads? I would like to be able to bolt them on and go but I don't think I will be able to. I plan on using these with a XE274 hydrallic flat tappet cam.

 

[hardline_42]

The description says that the outer diameter of the springs is 1.32". Vortec heads have 1.25" OD springs so the spring seats will need to be cut. Jakeshoe has a lot of good info on this.

 

[broken]

I have those springs and they didnt fit without machining. I've heard of some folks saying they did though...

 

[hardline_42]

Scoggin Dickey sells a "modified Vortec" head which is basically a stock head with the valve guide cut to allow for more lift. The description says cutting the valve guide is the only modification so I would assume the Z28 springs they use fit the stock spring seat. Try calling and see if you can get a p/n for the springs and whether or not they fit. Here's the link:

http://www.sdpc2000.com/catalog/353...olet-Cylinder-Head-w-Valve-Spring-Upgrade.htm