Hey guys, I just recently purchased a 70's 350 to start building for my car and I am looking at buying a set of vortec heads. I might buy them used so I have a few questions:
1. Is there any specific casting numbers I need to look for that will and will not fit my engine.
2.I have seen alot of L31 vortecs advertised as 96-99 heads, will thesed fit my 350.
3. I know I need a vortec intake, but do I need a special head gasket for vortec heads or can I just get them for a 350.

I appreciate the help guys.Thanks

 

1. No. All will fit.

2. Yes. See #1.

3. No. Head gaskets are not specific to the intake port design.

 

1. Go to www.Mortec.com and look for the last 3 digits; 062 and 906

Those are the two you want.

Don't be fooled by anyone telling you the 305 heads flow the same after larger valves are installed. They don't.

Avoid any that are not the two I mentioned above.

2. IIRC, that is the years you'll look for. The website I mentioned will tell you for sure. And they'll fit any SBC 350 except an LT1 or an LS1 (which isn't a 350 anyway ).

3. GM has Vortec specific gaskets, but as long as they're for a Gen II SBC, any will do.

 

Alright thanks guys, oh and RB83L69 I know the head gaskets dont have anything to do with the intake, but I figured since they made the heads to fit with a specifice intake they would make a specific head gasket for it. Thanks guys.

 

What is the difference between the 906 and 062 castings anyway? I have been porting both castings and have not seen any significant differences yet.

 

OH one more thing, will my stock rocker arms work with vortec heads until I can get self aligning roller rockers or not , thanks

 

Based on what I've read, they are the same on the intake side and inside the combustion chamber.

BUT -- one of the castings (906 ?) supposedly was designed for medium-weight trucks, and has a thicker valve seat on the exhaust. The valve seat was claimed to reduces the flow on the exhaust side and hence hurts performance. So the comment was to stay away from the 906 castings and instead look for the 062.

I can't confirm that, but it might be useful for someone to do so and post back here.

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Edit:

https://www.thirdgen.org/techbb2/sho...906+062+vortec

Edit #2:

https://www.thirdgen.org/techbb2/sho...906+062+vortec