Numbers on my heads help please

[rog_allen]

Well i took my valve covers off hopeing to see 906 heads and tne numbers were
2406516-6 and 08236 ??? Confused does any one know what these are ?
Thanks

 

[Cranky]

Yup, they are early model closed chambered heads. They came on many 383's up to and through 67. The hi-po 67 440 also had closed chambered heads...the 915 but with larger ports and exhaust valve. the 516 usually came with the smaller 1.60 exhaust valve. All is not lost with these as they can be upgraded with the 1.74 valve and with a little bit of port work, they can perform very well. 906's were open chamber heads and just doing a swap to them will lower your compression.

2406516 73.5cc, 2.08 intake, 1.60 exhaust, 1964-67 361/383/413

CC's on these are more like 80 and not 73 like most charts state. The 906's are right at 90cc

 

[rog_allen]

So someone put 383 heads on my 440?
Wow i got a mess

i thought i had a 1969 car engine with a balanced crank numbers on my engine say
t 440 e
9 20 x

 

[Cranky]

Big block heads are big block heads but that being said, the 906's didn't show up until 68 and were on both 383's and 440's. Many said that their 383 had 440 heads but that wasn't saying much. http://www.cowtownmopars.com/CastingNumbers.html
There should be a casting date and number on the side of the block....here's some info on block ID etc
http://www.yearone.com/updatedsinglepages/id_info/mopar/mopar casting numbers/castingnumbers.html

 

[rog_allen]

wow !!! thanks very much cranky !! theres alot to learn about this stuff

 

[696pack]

Big block heads are big block heads but that being said, the 906's didn't show up until 68 and were on both 383's and 440's. Many said that their 383 had 440 heads but that wasn't saying much. http://www.cowtownmopars.com/CastingNumbers.html
There should be a casting date and number on the side of the block....here's some info on block ID etc
http://www.yearone.com/updatedsinglepages/id_info/mopar/mopar casting numbers/castingnumbers.html

Actually Mopar started that themselves. It was the marketing department making something of nothing. They advertised the RRs and SBs as having 440 heads but in fact the 383-2 and 440 HPs all have the same heads.

 

[Meep-Meep]

The 516 heads have a flat intake port floor thus do not have the same flow characteristics as the 915 and the 906 heads. That said you can make them work. What I do like about them is the closed chamber. Easy .4 point of compression increase, and that change you should notice more than the intake port shape.

 

[71gtx]

67 440 4bbl lp has 915 heads but they have smaller 1.60 exhaust valve :VB toast:Casting Number Engine CID Year Intake Exhaust
4021051 360 1977-86 1.88 1.60
1737637 361 1958-59 1.94 1.60
1944705 361 1958-59 1.94 1.60
1737637 383 1960 1.94 1.60
2206324 361/383/413 1961-62 2.08 1.60
2206924 361/383/413 1961-62 2.08 1.60
2463200 361/383/413 1963 2.08 1.60
2406516 361/383/413/426 1964-67 2.08 1.60
2408520 413 1964 2.08 1.60
2402557 413 - 300J 1963 2.08 1.74
2402286 413/426 Max Wedge 1962-63 2.08 1.88
2463209 426 Max Wedge 1963 2.08 1.88
2406518 426 Max Wedge 1964 2.08 1.88
2406158 383/440 1967 2.08 1.60
2780915 383/440 1967 2.08 1.60
2780915 440HP 1967 2.08 1.74
2843906 383/440 1968-70 2.08 1.74
2951250 440 1968 2.08 1.74
3462346 383/400/440 1971-72 2.08 1.74
3462346 400/440 1973 2.08 1.74
3751213 400/440 Motor Home 1973 2.08 1.74
3769902 400/440 1974 2.08 1.74
3769975 400/440 1975 2.08 1.74
4006452 400/440 1976-78 2.08 1.74

 

[Cranky]

Actually Mopar started that themselves. It was the marketing department making something of nothing. They advertised the RRs and SBs as having 440 heads but in fact the 383-2 and 440 HPs all have the same heads.

Yup and yup....but even tho the heads have the same casting numbers, the main difference between a 383 2 bbl and a high performance engine (383 or 440) were the valve springs.

 

[rog_allen]

I PICKED UP A 1974 440 AWILE BACK THAT HAS BEEN BUILT CAMMED BORED... BLaaBLaaa blaaaa NEVER BEEN STARTED YET HAS REBUILT HEADS ON IT, NEW SEATS. GUIDES, VALVES, SPRINGS ECT.....
THEY ARE 4006452 ARE THESE ANY GOOD ? I NEVER PAID THEM MUCH ATENTION.. I JUST SEEN THE 452 AND WAS HOPEING FOR 906'S SO I FIGURED THEY WERE SMALL HEADS ???

 

[racedodge]

452's and 906's flow pretty much the same, only "real" difference is 452's came with hardened valve seats from the factory to handle the unleaded fuel.

 

[rog_allen]

Sweet !!! Thanks !!! Thats what i like to hear
so i should go with the 452's over the 516"s then you think ??
Compesion over valve size or valve size over a little more compresion ?