[V305]

I'm building a chevy 350 but a I want to use the vortec heads but I don't anything about what year, gaskets or casting number should I look for , what do you recommend?

[DoubleVision]

The 062 and 906 castings are the ones to look for, they came on 1996 and up chevy 350s. If you find a set, have them checked for cracks before you spend any cash on them, they are light cast heads and if you run them hot one good time they crack. They use regular SBC head gaskets. Its also important to know the guides have to be clearenced if your cam has more that .470 lift. And you must use self aligning rocker arms and a Vortec intake.

[techinspector1]

DV, not to say you're wrong, but GM says 0.450" is the limit.

[DoubleVision]

Tis cool tech, I seen so many answers to that question on the limit, I just put .470 as its the one I seen the most.

[V305]

Great info about the castings and the cracks I will consider this, and .450" is not to bad, maybe an edelbrock cam is enough, the modified vortec heads by scoggin dickey sounds cool but maybe next time

[F-BIRD'88]

Use a felpro #1255 intake manifold gasket for vortec heads.
If you do not want to machine the heads for cams that have more than .450" lift, (yes some of the OEM heads have enough for .470" lift), there are many special grind "lift rule" cams from mild to wild than have a .450" net lift limit. If you are after 420 horsepower or less, all you need is .450" net lift (combined with the right valve duration)

Makes a nice simple low buck street/strip 350ci Vortec motor that still delivers the goods.
eg: Isky "Lift Rule" .450" hyd mega cams for oval track.
A valve spring change is recomended. Can be done without machining the valve spring seats by removeing the damper from many of the popular stock diameter
"Z/28" type replacement springs. eg Isky #205D spring.
"Self Aligning" type rocker arms (stamped steel or aluminum roller) are required unless you have the heads machined for and install screw in studs and guide plates. Stock GM self aligning rocker arms work fine in these motors.

A easy affordable street/strip combo using OEM GM vortec heads with just a valve spring change would be:

a basic 350ci SBC short block with flat top pistons
+ 062 or 906 GM vortec heads
Isky #205D valves springs minus the inner damper
Stock OEM vortec retainers, seals locks and rocker arms
Isky #201278 camshaft 278-278 .450" .450" lift 234-234@.050" 106° LSA
Edelbrock Performer RPM Manifold and 750cfm 4bbl carb
1-5/8" headers 2.5" dual exhaust.
This combo makes more power and torque than the Edelbrock RPM cam will make without needing vortec cylinder head machining modifications to accomodate the .488"-.510" valve lift of the Edelbrock RPM camshaft.
Should use a 10" high stall torque converter and 3.73 to 4.10 rear gearing for best results. (same as the rpm cam needs)
Isky #201288 will make even more top end power all with just .450" valve lift.
Degree the cam in on a 102°-103° intake C/L for best results.

Very simple to build. Very impressive "street machine/cruiser" "street/strip" performance for low $$$s Very sexy idle sound.
www.iskycams.com

[curtis73]

I wouldn't worry too much about cracks. They get a bad reputation becuase they have thin decks, but in the 15 or so sets I've owned I've never seen a single cracked head. Thin decks does not mean they are crack prone. The design of the heads keeps the decks very rigid and they rarely crack.

The only two casting numbers for the 350 vortec heads are 062 and 906. Some of the 906 heads have different valve seats that ever so slightly restrict flow, but a good valve job will make them pretty much equals. Put it this way, I have one of each on a mild performance 350 and I don't lose an ounce of sleep over it.

[CNC BLOCKS NE]

We have used alot of the 906 vortecs on the circle track engines we build we use bowl hawg which will blend the lip of the seat in and we do a little more deshrouding on the intake side the guides machined, screw in studs and guide plates.

We are only allowed 11:01 and we use a Ford flat tappet cam around .560 lift and a 600 Carb, 1.94 and 1.5 valves andthe best dyno numbers we have seen have been around 515 horse and 485 on the torque.

And as far as cracking out of about 40 cylinder heads we have seen 3 crack.

The Vortec Bowtie head with a 180CC runner make better power and the new designed 225 runner Vortec Bowtie heads we consider one of the best cast iron 23 degree heads out there.

[Vortech 4.3]

when i was doing my heads, vortec 4.3's. i found that i could run a nearly .500" cam without touching the guides. but i bought the tool anyway and made em safe.

[techinspector1]

Originally Posted by Vortech 4.3

when i was doing my heads, vortec 4.3's. i found that i could run a nearly .500" cam without touching the guides. but i bought the tool anyway and made em safe.

Recommended is 1/16" to 1/8" static clearance between retainer and guide/seal at full lift, so yeah, you could maybe see a little clearance at 0.500" lift, but it wouldn't be the 1/16 to 1/8 recommended. Just including this for the newbies who might think a 0.500" lift is ok with no mods to the guide.

[Slimpikins]

Go to chevy high performance and look at a few vortec articles before you start your project. The worst thing is when you run into an unplanned problem and have to stop and look for solutions.
By now I'm sure you know that you have to buy a $200 intake manafold, because the intake runners are actually taller and narrower than any other intake. Pluss they only have 4 bolts tat are angled straight up. They have mentioned the valve clearence issues. Also if you want to use 1.6 rockers you have to grind out the pushrod slot and use self-aligning rocker arms.
You can get a set of proform roller rockers for $160-170. You can actually get away with a set of LS6 beehive springs from cnc motorsports for a little of nothing and they will fit into the spring pocket. The only bad thing is they are set up for 110lbs of seat load at 1.8" installation height. You are going to have a 1.7" install height. It brought my seat pressure to 135lbs.
If you ask me the best intake gasket to use is Pt#MS98000T it's pricy but you can order it from your local oriellies, autozone, or whoever carries fel-pro gaskets. I've taken my intake manafold off twice and it still doesnt leak. That is another thing you need to be aware of is that the biggest cause for the vortec engines to run hot and crack a head was a leaking intake manafold gasket.
You can get the valve guides machined down for a little of nothing from your local machine shop. FYI have them CC the combustian chambers. I measured mine and they are actually 65.5cc. So in order to get the compression that I wanted to run I opted for a .015 felpro gasket. Factory replacement is .041. Cam choice is left to you. You have to decide whether you want your power to peak around 5500 RPM for streatability or 6000+ RPM for all out power. The biggest advantage to the vortec heads are the small 170cc intake runner. You can actually run a little bit bigger cam and still have the vaccuum and throttle response you want while flowing just as well as a 200cc World Products Sportsman 2 boat ancors.
Hope this helps

[Vortech 4.3]

Originally Posted by techinspector1

Recommended is 1/16" to 1/8" static clearance between retainer and guide/seal at full lift, so yeah, you could maybe see a little clearance at 0.500" lift, but it wouldn't be the 1/16 to 1/8 recommended. Just including this for the newbies who might think a 0.500" lift is ok with no mods to the guide.

right now, i don't remember what i was told. but i asked here, and i think it was .060, and thats about what i had. but, needless to say, its better to be safe and do it right. and thats what i did.

[Nothing's Easy]

Find a set of heads from a 1500 series truck/van/suv.. (vans had them till 2001) some 2500's and 3500's had the "bad" vortecs, you can't rely on casting numbers. Also you can get .550" of lift from an unmachined head. Just cost's $100 more for springs (which i'm sure is way cheaper than paying a machine shop) Bee Hive Springs

[V305]

So what beehive valvesprings should we use?
Comp Cams 26915 or 26918

[Nothing's Easy]

I think they're both the same one spring has a little more seat pressure than the other. You can find the specs on the comp cams website.