[curtis73]

I bought a longblock vortec 350. It came with one 062 head and one 906 head. Any problems?

I have a pertronix billet plug and play distributor. Does a stock roller cam require a special distributor gear, or can I run the one that's on it?

Anyone know the intake bolt torque?

Thanks

[stewartcannon]

they sent you a engine with 2 different numbered heads? never heard of that before. think i'd be on the phone. maybe that engine was returned with a cracked head or something and they slapped a new head on it and sent it out again.... or then again it could be absolutly nothing but i'd still call to just find out some more info.

[curtis73]

I'm sure that's not the case at all. I've been buying engines from this guy for years. Top notch work, but thanks. I know what to look for in a reman, and this guy does the best I've found.

Actually, low-budget stock builds like you get at the parts store come with different heads all the time. In fact more often than not they're different. Just wondered if these two vortecs were different enough to worry about.

[NWayne]

Originally Posted by curtis73

I bought a longblock vortec 350. It came with one 062 head and one 906 head. Any problems?

I have a pertronix billet plug and play distributor. Does a stock roller cam require a special distributor gear, or can I run the one that's on it?

Anyone know the intake bolt torque?

Thanks

This might help you. It was taken from the Gilbert Chevrolet site:
Inserted by GILBERT CHEVROLET
There is no difference between either of the Vortec head (P/N 12558060) castings except for a couple of minor external cosmetic details. The two casting numbers are 10239906 and 12558062. GM has and does take some of the P/N 12558060 heads made from either of these castings and makes alterations to them to better fit specific applications. When GM does this, they change the part number of the head. Buying Vortec heads used is risky unless you know what vehicle they came out of, what part number the head is, and what modifications where made to the head to make it that part number. You can not go by the casting number, as suggested by this article, you have to go by the part number of the head when buying used Vortec heads.

http://gilbertautoparts.com/frame.html?/products.html

[curtis73]

Great, thanks.

[NDNslicks4me]

actually they are different. the 062 is a car head and the 906 is a truck head. The 062 will have three triangles on it. The 906 head has a heavy duty exhaust seat the hurts exhaust flow. some minor bowl work will make them the same. or run as is, you'll never know they are different.

[curtis73]

They never put Vortecs in cars... did they? All of them should be truck engines.

[NAIRB]

Originally Posted by curtis73

I bought a longblock vortec 350. It came with one 062 head and one 906 head. Any problems?

I have a pertronix billet plug and play distributor. Does a stock roller cam require a special distributor gear, or can I run the one that's on it?

Anyone know the intake bolt torque?

Thanks

All of the 062 heads had just induction hardened style seats, while some of the 906 heads had induction hardened seats, and some of the others had regular exhaust inserts in them. I never could see much difference between the heads if they both used induction hardened seats, but the heads with inserts don't flow quite as well on the exhaust side. They normally won't crack like induction hardened seat will.

I've used all three styles of heads in performance applications quite successfully.

Vortec heads crack so bad, that it doesn't surprise me that you've got a set of mix n match heads on your engine.

I probably wouldn't sweat it too much. You'll not feel it on you posterior region.

Vortec heads weren't used in cars. The heads with the inserts seem more prevalent on 1 ton vans and trucks, while the other style of 906's and 062's were used on Suburbans and 1500 pickups.

[Vortech 4.3]

i would like to see what these inserts look like. do the 4.3's have them ?
i ported my 97 heads, and i didn't see anything that looked like an insert.

thanx

[curtis73]

Originally Posted by NAIRB

Vortec heads crack so bad, that it doesn't surprise me that you've got a set of mix n match heads on your engine.

.

I've read this before from you and I value your opinion but it makes me curious. Either you have had an abnormally bad experience with Vortecs or I've had an abnormally good experience with them. I have NEVER seen a cracked vortec head, even a set that we took off a dirt track car after the thermostat stuck. It ran about 5 laps at 7000 rpm screaming hot and didn't crack. Are you sure you're not confusing thin decks with an assumption of cracking? They do have thin decks, but I've never seen a cracked one. I've heard of them cracking, but no more than any other production head.

Anyone have an idea on the distributor gear question?

[NWayne]

Originally Posted by curtis73

I've read this before from you and I value your opinion but it makes me curious. Either you have had an abnormally bad experience with Vortecs or I've had an abnormally good experience with them. I have NEVER seen a cracked vortec head, even a set that we took off a dirt track car after the thermostat stuck. It ran about 5 laps at 7000 rpm screaming hot and didn't crack. Are you sure you're not confusing thin decks with an assumption of cracking? They do have thin decks, but I've never seen a cracked one. I've heard of them cracking, but no more than any other production head.

Anyone have an idea on the distributor gear question?

I was wondering the same thing. Sometimes I think some of these things are hear say. I
've know of a lot of people that have run these things and never had a crack.

[NAIRB]

I've bought vortec heads by the skid load, and I would say that 50% of them are busted. That doesn't mean they can't be fixed, but they are either cracked down the center exhaust port or up the center bolt hole. I've fixed both of these types of cracks, but it's not always easy or possible. I've seen the exhaust seats crack while installing guides with a muffler gun tool. The vibration would cause a crack!!

If the heads come off of a running engine, they are probably okay, but most of them will start to show the early signs of cracking up the center bolt hole. You have to look very, very closely to see it start. I would pin the crack and sleeve the hole. If the crack was really long, I would junk it.


Vortec heads that run in Suburbans, etc are subjected to lean burning mixtures and high exhaust temps. They are thin, the exhaust seat is so brittle from the induction hardening that they are very prone to crack there.

They are great flowing heads, but they are fragile.

These engines from the factory had dex-cool and were prone to leaks. A woman driver will usually keep on driving it, get it hot, and the heads are toast. These are the parts you find as core heads.

Once should be very careful when you buy these cores, and look very closely at the center exhaust seats and the center bolt hole.

[jimfulco]

GM says all their roller cams should be used with the melonized distributor gear. I don't know if it will fit an aftermarket distributor.

http://www.sdparts.com/product/10456...butorGear.aspx