I'm getting ready to purchase a set of 350 vortech heads for my 331. My question is, "What is the best vortec head castings?" I usually see the 906 truck vortecs on ebay. Are they the best or just the most prevelant?

What are the best heads ususally found on? I'm getting ready to cruise some local junk yards for some good starting stock.

Clyde

go here (http://216.239.39.104/search?q=cache:5lg0ZQ6N3dQJ:www.sallee-chevrolet.com/Cylinder_Heads/Vortec.html+vortec+head+casting+numbers&hl=en&ie=UTF-8) almost all the way down on the right side it explains the different casting numbers and which ones to avoid. there is also lots of other good info about other parts you will need and some of the modifications that can be done.

"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."

Actually I believe thats completely false. 906 and 062 are pretty much the same aside from some SLIGHT differences. I remember a magazing saying the 906's were junk but they later retracted that statement. Anyway, I know a few guys in the low 12's with 906's so I wouldnt "avoid" them.

Yes, they did retract that statement. Darn if I can remember what mag it was.

I've owned the 906 and the other 062 heads. I saw no difference in either when doing a valve job.

Honestly, you should be doing some work on the exhaust side anyway!

906 has pressed in exhaust seat, 062 are flame/induction hardened. At least that's been my experience on the 500 or so I've handled. The 062 is a bit easier to bowl blend/clean up, but that's about it. HTH

actually they say that the 906 and 062 are the same except that some of the 906 heads have the bad exhaust seat. there is no telling if they do or not except by looking at the seats. so if your gonna buy used from junk yard or ebay look at the exhaust seat. this could be tough from the outside. whith out taking the heads off and removeing a valve so i would just get the 062 heads if you couldnt be sure. none of the 062 have the bad seat.

Umass,

What are you referring to about the bad seat? Is it all of the exhaust seats or just a particular cylinder. How do i tell if it is bad other than being burn't or cut?

Clyde

I am under the impression that it is all the EXhaust seats. what i mean by bad is that there is an insert that is machined and pressed in that forms the seat. this insert seat kills the exhaust flow. i do not know what they look like I have the 062 heads. I would imagine that if you looked in the exhaust port you may see a ridge of some sort if indeed those heads had the bad seats. good news is though that if for some reason you get the heads with the bad seats they can be ported or machined to flow normal. so what i would do is look for the 062 or 060 heads. if you get the 906 heads they may either have the bad seats or not only way to tell is if you know what they look like.