mckenzie

i'm wanting to switch to vortec head for a 88 350 tpi motor that i have. i noticed 2 different castings for the vortec heads, 906 and 062. which is better? is there any difference in them? i have the 062 castings off a 98 chevy k1500 350 motor. thanks for any info. tom

FlamedROC

Like you said vortec heads came with 2 casting #'s. the better of the 2 are the 906 casting heads because they have like 20% better flow over the 062 heads. 062 heads come of the 3/4 ton trucks. So you have the lower flowing vortec head but hey man be happy you have vortec heads man those heads work wonders. But all in all 062 is less flow and 906 is high flow. Now remember if you bolt on those heads your goin to need the special intake base to be compatable with the vortec heads. SDPC sells them for around $400 hope that anwsers your question.

Jason

mckenzie

yes, thanks for the help. the 062 heads came off my uncles 98 1/2 ton 4x4. thanks again, tom

FlamedROC

No Problem man. Hey when u bolt them on and get some dyno figures let me know ok...

Jason

mckenzie

did some more searching on the internet, found this website that says the vortec heads had 2 casting numbers 10239906 and 12558062. no difference's were mentioned. www.streetrodstuff.com/products/115/.

FlamedROC

They are just giving the 2 types of heads. But still the 906 heads are the better flowing heads.

Jason

FlamedROC

Hey looking at what ur sayin about your IROC.. I have the same year IROC w/ a TPI. Just wondering what cam you put in and how did it help.

mckenzie

when i rebuilt the motor, (had block bored .030) i installed the comp cam for the 305/350tpi. it has .444 lift on both intake and exhaust. it helped some (i wanted to keep a good idle and vacuum so i didn't go too crazy) i'm looking for headers next. thanks, tom

Todds1987iroc

I think Fbirdta878787 has the heads reversed. The 906's are the ones that flow less. In Chevy high performance jan '03 issue on page 40 they state that the 10239906 heads are for 3/4 and 1 ton trucks and have specially harded valve seats thats kills low end and mid range lift flow. I had the 906's on my engine in my 69 camaro and they run good but I think the other casting is better.

mckenzie

i know that my heads (062 casting) came from a 98 1/2 ton 4x4. (as i removed the motor myself and install a new GM longblock) i don't know, i was just wondering if there is a difference between the casting numbers. thanks, tom

chevyboy07 91

ohh F U G G!! Can someone PLEASE verify what's what and what "flows better"?

Also, I have 2 sets one say "Made in Mexico" the other says "Made in Canada"....any knowledge on some possible differences?????

mich2112

iTrader: (1)

I concur with Todd. The article said to AVOID the 906's.

vortec nova

all remarks made about 906"s having less flow in hotrod magazine were retracted at a later date as these remarks were false. although it is advisable to blend the exaust seets to the port.

watajob

iTrader: (29)

Indeed:

http://www.sallee-chevrolet.com/Cyli...ads/Vortec.cfm

FlamedROC

Yup...Wow this is back from the dead. It has been stated that and proven that the 062 head do not flow more but have a stronger exhaust seat.

Uadean80

Sorry to tell ya, but Jason has it backwards. The 062 vortec heads are what you want for performance. The 906 vortec heads have a special hardened valve seat which limits its lift slightly compared to the 062 heads. But dont take either of our words, its the age of information & its literally at your fingertips, 1 thing ive found in these forums, each person has their own view & belief on any given subject, with that in mind, asking a public question is really just an open invitation to debate. Just read thru articles posted by published sources, HotRod magazine and the likes, youll find the info you seek, without having to filter through everyone elses opinions or beliefs. Just speaking from experience. Here's a good article from a well known, published source that was written by people that have actual, first hand knowledge on the subject.

http://www.onedirt.com/tech-stories/engine/a-guide-to-vortec-vs-oe-small-block-chevy-heads/

Cary I. Fowler

amen

Abubaca

iTrader: (3)

I realize this is an old thread, but I couldn't possible disagree with this statement more fully. Published articles are bought and paid for, and written by enthusiasts just as fallible as anyone, and often have no more knowledgeable than many of us in these forums. Is there mis-information on forums, sure. -as well as some jack leg know it alls who don't know it all. You also have guys who helped BUILD these cars, or heads, or valves, or gizmos or gadgets back in the day, as well as guys who have built engines over and over and over. Been here about 20 years, and I've seen many of the big manufacturers and publications asking US questions about this or that. No I'm sorry, the best info is hands down, on the forums.

You just have to know how to sort through it all, -which I do concede can be difficult at times. Still, when I receive 10 opinions, I can typically put together a good picture of who knows what, who is the know it all new kid and who is the guy who knows his stuff. And sure, sometimes it may bite ya, but no way I'm reading an article in a magazine and taking their word for it! The metric crap ton of garbage info out there in the magazines would amaze you.

Chevyman956

so anyone saying are different for flow is wrong the pattern to cast is literally the same the only different is the material used for the valve seat itself.

• Two Vortec castings were used from 1996-99 on GM CK trucks ('00 in vans) and SUV's utilizing the Vortec 5700 350 engine. The #906 and #062. The #906 casting head was available in two versions. One has an Inconel exhaust seat, and the other has the conventional induction hardened 3-angle grind on the exhausts as per the #062. The #906 with Inconel seat does not intrude into the exhaust port. It was used primarily on the HD and 1-ton truck applications where sustained towing of heavy loads & weight up inclines could cause eventual damage to a standard induction-hardened exhaust seat from excessive heat.
• The only difference between the #062 and #906 Vortec head is in the exhaust seat of the HD/1-ton truck #906 version, as described above. The #062 has a 3-angle grind on a standard induction-hardened seat, as does the non-HD #906 head.

Fast355

iTrader: (2)

Old thread but since people are on the subject. Mexican 062 Vortecs flow like crap. 218 cfm peak at 0.400 and dropped to 210 at 0.450 and beyond (heads off my Hecho en Mexico crate engine bought in spring of 2006). 059 305 Vortec heads outflowed the mexican 062 garbage. My Canadian 906s (off my 57K mile L31 97 Van with a rod hanging out of the block) peaked out at 242 @ 0.500. 906s were better everywhere and the factory 97 engine made noticeably more power yet they also had the HD single angle hardened seat. Both were flowed on the same bench with the same exact hardware and methods. The 062s both cracked, the 906s are still good. Etec170s wiped the floor with both castings. Better power and better fuel economy from the aluminum heads. I could only run 28-29° of timing on the iron heads with 91 octane before encountering detonation and the aluminum heads liked 34° by 2,600 rpm. Torque curve was much stronger with the aluminum edelbrock heads.