difference in heads, casting numbers on mopar heads Options

[w0nderer_22]

everyone talks about the 452 an 906 heads, what about the 213 an 975 heads, they got the same size intake an exhaust ports, so is the 452 an 906 a better head?

[msroadrunner]

everyone talks about the 452 an 906 heads, what about the 213 an 975 heads, they got the same size intake an exhaust ports, so is the 452 an 906 a better head?

There is a good write- up in Mopar Muscle here that describes some differences. I imagine that the 213 and 975 heads are similiar to the 346 heads I used on my motor, and it screams!

http://www.moparmusclemagazine.com/techart...eads/index.html

[w0nderer_22]

There is a good write- up in Mopar Muscle here that describes some differences. I imagine that the 213 and 975 heads are similiar to the 346 heads I used on my motor, and it screams!

http://www.moparmusclemagazine.com/techart...eads/index.html

thanks for the info msroadrunner, i was curiois because i hv a set of 213s one is cracked around the intake valve, the machine shop say they can fix this since they have to harden the seats, but i hv access to the 975 heads witch already have the hardened seats.

[azmusclecar]

everyone talks about the 452 an 906 heads, what about the 213 an 975 heads, they got the same size intake an exhaust ports, so is the 452 an 906 a better head?

I believe (and I could be wrong) but I think the 906 heads are closed chamber whereas the rest are open. Also, some of the later 70s 440 had heads that contained two holes for water channels (from the block). These heads generally sat on the 440 type 3 block. If you have a block with two water channels and heads with one you will end up with a water flow issue.

[MyMopar]

Incorrect. The 915 heads are the only closed chambered heads and were available on 1968 440 big block motors only. A few years ago I had a pair of NOS 915 closed chambered heads, and they fetched $2000.

Richard

[nz383man]

2780915 383/440 1967 2.08 1.60

2780915 440HP 1967 2.08 1.74

As a very rough rule of thumb I think you will find most '67 & earlier heads were closed chamber & most likely all '68 (906) & later heads were open chamber.

It was the '67 440HP 915 head that was the best one to get as it was the only closed chamber head with the bigger 1.74" exhaust valves (excluding max Wedge)

[mrmopartech]

Things that vary from head to head castings:
Port volume in CC,s
Short turn height and shape
Bowl design
Valve size
Chamber shape in CC,s weather open or closed chamber
CC,s of chamber can vary up to 10cc,s even if the same shape is used
Push rod pinch on the intake port wall
Valve guide boss shape and size,and height
casting flash in bowl
These are just some of the items,mrmopartech

[reddodge]

Get the mopar performance book on the big block engines. A lot of good information on these heads there. In short all the late open chamber smog heads flow about the same.

[Bigun426]

Another source for closed chambered heads is 2046516 that was used 1964-1967 on the 361's. I have a set that came off a 66 361 but they have the 1.60 exhaust valve. It was a 2bbl. engine that had a advertised 9:1 compression ratio. Also in 64 the 426 max wedge used 2406518 heads and they had the 1.88 exhaust valve. May be a sleeper performance head being the same head with the last two numbers designating the exhaust valve size 16 for the 1.60 and the 18 for the 1.88.