open or closed chamber cleveland heads, need help ASAP

[jterry831]

Hey guys, I have a cleveland with 4v heads that have a casting number of 9m11 on them. Are these open or closed chamber heads?

Thanks!

Jimmy

 

[D.Hearne]

That's the date code not the casting numbers. Do they have a "4" cast into one corner next to the valve cover rail ?

 

[rbohm]

the only way to know is to pull the heads and look. even in 1970 there were two versions of the 4V heads on the 351c.

 

[jterry831]

Is there any other way to tell if they are open chamber or closed chamber besides pulling the head off? They have a 4 in the corner of the head next to the valve cover.

thanks for the info!

 

[commonrail]

Post the casting number on the site. Most non boss 351C heads are DOAE-N

 

[dodgestang]

Is there any other way to tell if they are open chamber or closed chamber besides pulling the head off? They have a 4 in the corner of the head next to the valve cover.

thanks for the info!

No way to tell open vs closed with 100% accuracy without turning head over and looking at the chamber.

1970 date code = much higher probability for closed chamber
1972-73 = much higher probability for open chamber

 

[96 DOHC Cobra]

Since you know for sure that the heads are 4V heads (the "4" in the upper corner), and the casting date is "9M11" (December 11, 1969) they have to be closed chamber. The only 4V heads used on 70-71 models were closed chamber heads.