COOLTED

Again, I have a head question. I purchased the Vortec heads from the local GM dealer and have purchased a 268xe cam. I am getting some conflicting answers as to the max lift allowed. I have read that I can use the cam without machining the head, and I have also read the opposite. Will the Comp 268xe work with vortecs without machining?

OMF

Your XE268 cam has a lift of .477 intake, and .480 exhaust.
There are different claims for the vortecs anywhere from .420 to .470 lift.... depending on who you talk to.
In your case I think you are at the upper end of unmodified valve lift.
I would suggest assembling some verylight testing springs (the hardware store variety) and assemble the head on the engine using an old head gasket that has been compressed but is in good shape. Tighten it all down, and make sure at max lift you have .050" between the valvespring retainer and the valve guide.
If you can't get that .050" you need to cut down the valve guide just enough so you get it.
A very easy procedure you can do yourself if your halfway to handy, with a guide cutter you can get from the speed shops, or just take it to the machine shop and ask them to cut the guides down "x" inches.

I did this myself on my vortecs, and am sporting a max lift of .544 with 1.6 rockers.

COOLTED

Ok. I should be ok with just cutting the guides. Thank you sir!

OMF

here is the cutter I used...

https://www.summitracing.com/int/par...4726/overview/

COOLTED

Thank you.

cardo0

What did you decide on for valve springs? I believe you can get a stepped spring retainer for the GM beehive springs that allow greater valve lift w/o cutting the guides. Try a Google search and I read a lot of the vortex head swaps on Third Generation dot Org. And I believe Comp Cams has a valve spring package for vortex heads.

Hope this helps.

gkull

For higher lift you can do several things. +.100 longer valve stems or +.050 retainers. Springs can have different coil bind height and max lift.

Cutting deeper spring pockets or the guide is a bubba idea on a already weak head

cv67

Retainers probably your cheapest route make life easy

COOLTED

Using the stock springs, they'll work, right? The retainers are a great idea, but with the low end guess of max .420 lift I don't see that .050 being enough for a .480 lift cam. I'm gonna take them apart this week and get measurements. Thanks for the replies!

daustin

I did this a couple years ago. I used the comp tool listed above to reduce the diameter of the valve guide and another comp tool to cut the guides height down. Left the spring pockets unmolested and used the comp spring kit for Vortec heads. Used the xe268 cam. Runs like a top and i did that in an afternoon, easy.

Don