Vortec 906 heads

[Dreworr123]

Hello all,

I have a sbc with 906 heads casting number 10239906. I know this is a popular casting but Ive aquired a set with the casting 13120906. Are these both the same heads? I just see no listings of this number at all and wasn't sure if someone has come across this.

Thanks in advance,
Drew

 

[bman440440]

10239906...96-up...350.........."Vortec 5700", "L31", 64cc chamber,
170cc intake port, 1.94"/1.5" valves

on the 13120906 heads are you sure about that #? that # is not listed in any of the chevy books

 

[Bondo]

Ayuh,.... Vortec heads were only cast with 2 different numbers, 906, 'n 062,.....

The 062 heads are induction hardened exhaust valve seats,....

The 906s came with induction hardened valve seats, or the more desirable inconel exhaust seat inserts,....
The only way to tell the difference is to Look at the exhaust valve seats,....
The inserts are visibly different,.....

 

[Dreworr123]

No Title

 

[Dreworr123]

I will compare the exhaust seats before I take them home thanks. I just figured gm would atleast have that casting number listed.

 

[bman440440]

can you take more pics of the head?? now I'm really wondering what they are

 

[Dreworr123]

No Title

Well theyre not GM I don't think. Both heads have no casting humps or anything on the ends. They also have frost plugs. one of them says ACH so I'm assuming these were made by American Cylinder Head Inc. They don't seem to have the inserts on the valve seats unless they were blended really well. One positive is they don't have pressed in rocker studs. I also found the valve stems are all ground down about 0.025" at the section in either the exhaust or intake cavity. I guess for better flow?
Not sure if its worth using these heads or not. Anyone have an opinion?
Thanks again

 

[NHGuy]

I'd take them to a machinist for professional inspection. They could be fine. But they could be trouble. Are they priced well?
There is a new intake valve on the chamber to the left in pic 5. And the exh valve in the visible chamber looks hinky. Something smacked it.
Those heads look to have smoothed valve guides in their ports. Perhaps they have been polished and or ported.

 

[Tempestnova]

No Title

Well theyre not GM I don't think. Both heads have no casting humps or anything on the ends. They also have frost plugs. one of them says ACH so I'm assuming these were made by American Cylinder Head Inc. They don't seem to have the inserts on the valve seats unless they were blended really well. One positive is they don't have pressed in rocker studs. I also found the valve stems are all ground down about 0.025" at the section in either the exhaust or intake cavity. I guess for better flow?
Not sure if its worth using these heads or not. Anyone have an opinion?
Thanks again

I like to know more I ended up with a set of these heads also I cant find any info on them please help thanks

 

[Tempestnova]

Hello all,

I have a sbc with 906 heads casting number 10239906. I know this is a popular casting but Ive aquired a set with the casting 13120906. Are these both the same heads? I just see no listings of this number at all and wasn't sure if someone has come across this.

Thanks in advance,
Drew

was wondering if you found anything on theses heads thanks Rudi

 

[achris]

4 year old thread. Please start your own if you have a question.