Re: Heads up for any of you guys thinking about going the vortec route on your small block.

by The Dude Thu Apr 15, 2010 10:49 am

BlackChevelleSS wrote:hey rago found out that three sets of the 4 of the vortec heads we got were cracked right at the exhaust valve seats on the two inner cylinders.

So 6 out of 8 heads were cracked? Damn that doesn't say much for the Vortec head's reliability. pale

What castings are they?

by BlackChevelleSS Thu Apr 15, 2010 11:16 am

there were 2 different castings, dont remember the numbers tho

by Jim_Rockford Thu Apr 15, 2010 11:39 am

Thats one of the problems you run into with the USED heads, being as how they all come off trucks and truck get WORKED I would pick up a new set if I was in the market for some,

by The Dude Thu Apr 15, 2010 12:04 pm

For that matter, just dish out a couple hundred extra $$ for a set of aluminum heads that are:

A) Superior in design
B) Lighter weight
C) Accepts old school intakes, which helps with the cost

I'd love to try a set of Vortecs, but not if they are just lightweight castings that crack. I know of several smog castings that lasted longer than 10 years in trucks.

by Jim_Rockford Thu Apr 15, 2010 12:17 pm

Naa they are good heads, Its just cheaper to buy New , by time to buy used and then take em to get cleaned and checked and decked you have spent to same amount or more on getting old ones gone over as you would have on a new set, hell maybe even enough to get the scoggins and dicky modded ones to handle more lift. remember the used ones are coming up on being 15 years old.

by Limey SE Thu Apr 15, 2010 3:38 pm

vortec heads came in 062 which the masses like more

and 906 which I have for sale with manifold 400 and have been already gont through and ready to bolt and go with the polished NIB manifold and NIB centerbolt covers

by The Dude Thu Apr 15, 2010 3:55 pm

There were also other castings that are less desirable. That's why I asked Dan what casting he had. Post up more info on your heads in the G3GM swap meet section, lol.

by MichiganMuscle77 Tue Apr 27, 2010 8:18 pm

The easiest way to identify a Vortec head is by the sawtooth pattern cast into the front. Look for casting number 12558062, but avoid casting number 10239906, which has a modified exhaust seat and loses 20 percent of its flow at 0.120-inch lift.

http://www.chevyhiperformance.com/howto/97458/index.html

I almost had a set of Vortec heads for $200 out the door, but they were 906.

by Limey SE Tue Apr 27, 2010 9:39 pm

they are the same............... if I can find the article it was a mistake by hot rod and they recanted later in print about the 906 and 062 casting they are equal

by The Dude Wed Apr 28, 2010 10:34 am

SOME 906 heads are equal to the 062 castings. There are 906 heads with the hardened exhaust seat. They only came on HD trucks if I remember correctly. Typically you want to look for these two castings, as there are other less desirable vortec castings out there. 062 are the cream of the crop heads that people make power from, but 906 flow just as well if they don't have the hardened exhaust seat. Even the bad 906 heads can be modified to flow though.

by Limey SE Wed Apr 28, 2010 12:00 pm

Ok, lets straighten this out,,, there is no difference between the 906 and 062.

Chevy High Performance wrote an article in like 98 that started this rumor but then 2 months later they apologized for the mistake. They flow the same and it has been proven time and time again !!!

Chevy High Performance magazine did an article on Vortec heads. I do not know when the article was written because the don't put the date in the article on the website but this is what the article says"

In 1996, GM incorporated the port design from the very successful iron LT1 engines used in the Impala SS, which was improved over the aluminum LT1 Corvette and Camaro engines.
In essence, the Vortec head uses the iron LT1 chamber intake and exhaust ports in a standard-water-flow iron head. These production Vortec heads were used in the new Vortec 350ci engine intended for ½-, ¾-, and 1-ton Chevy pickups. Amazingly, this mundane, production-based 1.94/1.50-inch valve head performed better than the iron Bow Tie head.
The deal of century occurred when GM Performance Parts decided to sell these heads as complete units for under $500 per pair, ready to bolt on. For you junkyard hunters, be forewarned that some ¾- and 1-ton trucks came with Vortec heads equipped with a specially hardened exhaust seat that kills low- and mid-lift flow. Casting number 10239906 should be avoided. "

Now I don't know what this means to anybody or about anything but it does give me something to think about.
Are most people using these heads and are they happy with them?

This is the article that was withdrawn/corrected

This is the article that they then took back. the 1ton+ 906 heads have a hardened insert on the exhaust side that was more restrictive but its a tiny tiny percentage of vortecs and you can see it once the valve is removed.

by The Dude Wed Apr 28, 2010 1:32 pm

Limey wrote:Ok, lets straighten this out,,, there is no difference between the 906 and 062............
..........This is the article that they then took back. the 1ton+ 906 heads have a hardened insert on the exhaust side that was more restrictive but its a tiny tiny percentage of vortecs and you can see it once the valve is removed.

Rago wrote:SOME 906 heads are equal to the 062 castings. There are 906 heads with the hardened exhaust seat. They only came on HD trucks if I remember correctly. Typically you want to look for these two castings, as there are other less desirable vortec castings out there. 062 are the cream of the crop heads that people make power from, but 906 flow just as well if they don't have the hardened exhaust seat. Even the bad 906 heads can be modified to flow though.

Aren't we saying the same thing here?

by Limey SE Wed Apr 28, 2010 1:38 pm

I was just finding the article is all my friend............. and notice that it says only 1 ton and up trucks had the less desirable style ones

by The Dude Wed Apr 28, 2010 1:46 pm

Yeah, I wasn't sure if it was 1 tons or just the HD versions. Hopefully we helped dispel some myths though.

I think I'll stick with the swirl ports personally. Better exhaust flow than vortec, good gas mileage, & killer low end. Just don't expect to build a screamer with them. Very Happy

by MichiganMuscle77 Wed Apr 28, 2010 7:26 pm

I'm gonna go ahead and grab those heads from my mechanic friend then. 906 casting, came off a half ton 99 suburban.

Will go nice with my car and headers. Will go even nicer when I build my motor into a 383 Smile

by The Dude Wed Apr 28, 2010 7:53 pm

Michigan, I thought you had a Cutlass?

by MichiganMuscle77 Wed Apr 28, 2010 8:32 pm

Rago wrote:Michigan, I thought you had a Cutlass?

Oh i do.. chevy motor though.

by Limey SE Wed Apr 28, 2010 9:08 pm

he has the 355 chebbie in his Rago don't you pay attention scratch

LMAO

by Limey SE Wed Apr 28, 2010 9:10 pm

MichiganMuscle77 wrote:
Rago wrote:Michigan, I thought you had a Cutlass?

Oh i do.. chevy motor though.

Chevy 350 - Vortec Heads, RV Cam, Edelbrock intake, Holley 600, headers and Flowmaster 3" center dumps, 3.73 rear end.

by MichiganMuscle77 Wed Apr 28, 2010 9:39 pm

Limey wrote:
MichiganMuscle77 wrote:
Rago wrote:Michigan, I thought you had a Cutlass?

Oh i do.. chevy motor though.

Chevy 350 - Vortec Heads, RV Cam, Edelbrock intake, Holley 600, headers and Flowmaster 3" center dumps, 3.73 rear end.

Yep, except for the vortec heads part - I thought the ones that are on it now were vortec, but they're not. They're just k-motor heads (from a pick up truck). Of course that'll be changed soon.

by dragons_lair59 Thu Apr 29, 2010 6:28 pm

ok guy for slim roller tip rockers best bang for buck is proform roller tips. and lt vs. ls as a mechanic hands down ls motor and to resolve the C.O.P issue get the conversion to msd dist. mounts to front and carb and wahla normal wire price and more power then you can shake a stick at and lighter than any other small block (unless iron truck block) but the ls heads flow more in stock then any after market sbc head on the market. but then again this is just my humble opinion. and if i had the 14 large id be dropping a 427 ci lsx in my monte

by novaderrik Thu Apr 29, 2010 8:13 pm

Limey wrote:
MichiganMuscle77 wrote:
Rago wrote:Michigan, I thought you had a Cutlass?

Oh i do.. chevy motor though.

Chevy 350 - Vortec Heads, RV Cam, Edelbrock intake, Holley 600, headers and Flowmaster 3" center dumps, 3.73 rear end.

what is an "RV cam"? and how does it compare to a "3/4 race cam"?
i've been playing with cars for over 20 years, and have never gotten a firm definition for either of those terms.

as far as factory installed vortec heads- there were only 2 different castings that were identical in every way except for the foundry where they were cast and the hardened exhaust seats on some of the 906 heads. i believe the 906 casting with hardened seats is the one that they sell over the counter as a service replacement- which means it's the one you get if you order a vortec head from Summit or Jegs or wherever. i've also read that they changed the castings somewhere along the line and the newer castings aren't as good as the older castings, but still have the same casting numbers and markings. we're not talking drastically worse- flow is off a couple of percent- but still enough to make people want to avoid them. i'd take aset, since they are still better than any other factory head. i think the only way to tell the new vortec from the old vortec is by looking at the script of the casting numbers- the newer numbers are slightly bigger and blockier looking and the castings are a bit smoother than the earlier heads.
GM also sells the "off road use only" Bowtie vortec heads in a few different configurations, and some even call the aluminum Fast burn heads a "vortec" head, despite having a different combustion chamber layout that isn't as efficient as the production vortec chamber.

by JB2wheeler Thu Apr 29, 2010 9:09 pm

"RV cam" and "3/4s race cam" are slang terms, both meaning about the same thing. The RV cam is a cam that is kind of hot but not enough hot to make an engine hard to handle in heavy traffic carrying a heavy load. JB

by 1973chevelle Thu Apr 29, 2010 10:06 pm

we have the Vortec Heads on my moms truck and ours came with the valve covers and we got one of the chrome intakes for the Vortec heads, it all looks and works great!!

by The Dude Fri Apr 30, 2010 12:25 am

3/4 cam was a term used back in the stone age days before people actually cared or knew anything about real cam specs. Crane generically threw the term around up until their demise on their Energizer line & possibly others. Basically it was a cam in the range of 220-230 duration @.050 & a tight lobe separation for a good lope. Most people that have a cam with lope will claim a 3/4 cam if they have no clue WTF they are talking about to sound knowledgeable to non- car enthusiasts. We know better though. Smile

An RV cam is a small grind, nearly stock used primarily in tow vehicles & ...you guessed it... Recreation Vehicles. Yet again it is a generic term thrown around by cam companies. Comp Cams calls their 252HE an RV cam, Isky's RV cam is a 256 grind, several small companies make a generic "RV" cam kit & they are all around 250-260 deg advertised duration.

by Sponsored content