Vortec 350
 

I will be building a 1998 Vortec 350 for one of my old cars, and I am trying to find out how to build it. I have read that the vortec heads will not work stock with a higher lift cam. What exactly needs to be done to them to get over 500 lift? I went to 2 machine shops and they did not know. I have read that I can just get new beehive springs and they will work, and I have read that the heads need machine work. The motor will be a street motor, and I don't want to lose low end, so I am thinking a cam for 1500 RPM's and up. Something like 218 duration @50 tou, and a little over 500 lift, but I have not picked a cam yet because it will also depend on what the heads can take. Thanks.

Re: Vortec 350
 

I believe you have to run a longer valve and run screw in studs instead of pressed.

Re: Vortec 350
 

If I remember right, the biggest issue is the valve guides are too tall where you run into clearance issues between the valve guide seal and the retainer.....easiest fix is to machine for teflon seals and shorten the valve guides at the same time....

I'm sure someone on here has some first hand experience and can chime in.....

Re: Vortec 350
 

Stock vortec heads can handle .480 lift max...my cams lift is .479. To be on the safe side I grinded down the valve spring retainers. You can grind 1/16-3/32 and it should be good for up to .530 lift. You should still check your clearance to make sure nothing hits. This of course is if your on a budget, if not just get you some "Z28" springs and call it a day...

Re: Vortec 350
 

First off if your machine shop doesn't know what to do stop going there. On the vortecs you have to cut down the valve guide height and spring pocket diameter. Jets,summit and others sell a tool to do this and it's not very hard. The behive springs are good but $$$$! I would like to get my hands on a free Vortec block and build a nasty shortblock for my heads but if I spend any more money on a motor I'm going LS!!! Good luck on the build and show pics!!!
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Re: Vortec 350
 

You can run the beehive springs with the appropriate retainers, and be able to run a cam with probably close to .550" valve lift, without any mackine work. Although with a cam with that much lift, I would definitelt recommend converting to screw in studs. With any of the standard type SBC valve springs, machining will be needed. Either way, you should always check your retainer to valve seal clearance.

As for the correct part numbers for the springs and retainers, I would suggest a call to either Comp Cams or Summit racing. Tell them what you're wanting to do, and they will be able to set you up. This ia a very common upgrade.

Re: Vortec 350
 

Anything and everything you ever wanted to know about the Vortec heads,, and 56 pages more of questions you never thought to ask :)

http://www.nastyz28.com/forum/showthread.php?t=56505

Re: Vortec 350
 

definately either pin the studs or get screw in.

Re: Vortec 350
 

Kevin.
I actually had to get extra long drill bit and roll pin in a few studs on my moms truck motor in position.