Small Block & Big Block Chevy Specific - What Vortec Casting To Stay Away From?

I remember reading about a casting # that was made in mexico or something like that that sucked. I found a guy that is selling a set of vortec heads for $250 I was going to get them based on what casting #.

I also herd something about cam lift limitations on these heads.
i have a 388 with KB Flat Tops Eagle bottom end and rods
and a COMP Cams 12-213-3. You guys think this setup will be decent?
I was thinking roller cam can I go bigger?

Stay away from 305 vortecs, they have the good ports but the chambers are not heart shaped.

The 062's are the best I hear, they came on later model trucks and service replacements.

The 906's are rumored to be the bad ones. I've had 3 sets of 906's two sets were just like the 062's, one set had some hard exhaust seats that I wanted to blend into the bowls but they were so hard my porting tool wouldn't remove any material from them. These seats appear to have a slightly smaller inside diameter also. I'm sure a machine shop could open them up.

I've never seen any vortecs that said they were made in mexico.

Stay away from 305 vortecs, they have the good ports but the chambers are not heart shaped.

The 062's are the best I hear, they came on later model trucks and service replacements.

The 906's are rumored to be the bad ones. I've had 3 sets of 906's two sets were just like the 062's, one set had some hard exhaust seats that I wanted to blend into the bowls but they were so hard my porting tool wouldn't remove any material from them. These seats appear to have a slightly smaller inside diameter also. I'm sure a machine shop could open them up.

I've never seen any vortecs that said they were made in mexico.

Yeah, I've had a set of 305 Vortecs and I have a set of Ported 906's now. The 906 is fine if you take the time to hand blend the exhaust on it, otherwise it's an identical casting to the 062. I had no problem opening them up with my carbide burr, I have no idea what you were using though.

I had no problem opening them up with my carbide burr, I have no idea what you were using though.

A brand new carbide burr. I ported a lot of heads with no problems. But this one set would just give off a reddish orange spark when trying to do around the exhaust seat. I've even done other 906's that ported with no problems.

A brand new carbide burr. I ported a lot of heads with no problems. But this one set would just give off a reddish orange spark when trying to do around the exhaust seat. I've even done other 906's that ported with no problems.

Huh, I don't know bro. My set must have been like your "other" sets, I just didn't have a problem, no doubt you did, I would like to see the casting, it would be interesting!

I would like to see the casting, it would be interesting!

That engine has long been sold so no pics. But you know how the normal ones look, these you could see dark black around the exhaust seat after cleaning. I'm guessing some sort of heavy duty seat insert.

its an Inconel exhaust seat...Extremely hard.