Big Block heads question • The Dodge Challenger Message Board

by **Jon-D** » 25 Mar 2001 22:37

Does anyone know how to translate a set of Big Block heads by their casting number? I have a set that are # 2780915-6 that came off a 60's Chrysler 383/automatic. Are these worth keeping for street use?

by **Dave-r** » 26 Mar 2001 7:45

Yes.
2780915 is the 1967 High Perf. 440 head. I believe these had the same valve size and ports as the famous 1968-70 '906' heads but with a smaller combustion chamber.

by **Jon-D** » 26 Mar 2001 12:01

Thanks Dave!

by **frank....** » 19 May 2001 2:48

dave is right ..the street name for them are 915s

by **DED** » 18 Jun 2001 17:29

Hello
I just found out that my 440 in my challenger has heads with casting number 4006452, wich means that they are from 76-78.

Does annyone know how big difference it is between 1967,1968-70 heads and 76-78 heads.
Do they have lower compression ?, How much lower?,
Do they flow worse?

I alsow have a intake manifold with a number that I can't find anywhere the number is 3830783
I'm not shure about the last two didgits, it can be 38, 33, 93, 98
Is it possible that this intake is alsow from 76-78 something. The intake has fieringorder and distrotation marked, so I asume it is some kind of MoPar original.

by **dave-r** » 18 Jun 2001 18:53

The heads you ask about are all basically the same with the same sized valves and good port flow.
However the 1967 '915' heads are of a 'closed chamber' design. From 1968 they moved to an 'open chamber' design which gives better flow around the valve openings into the chambers and also promotes a better burning of the mixture. These are your '906' heads.

The later heads are all quite good but the intake was flattened out a bit to meet emmissions standards and then extra cooling passages were cast in.

The 1976-78 '452' heads were the last of the breed and came as standard with hardened valve seats. These are the best heads to use these days with unleaded fuel and work well on any 440. They flow slightly less than the '906' heads but simple porting takes care of that and if being ported to the max are in fact easier to do than '906' heads.

I don't have a listing for that intake manifold because my books are old (like me!) but judging by the 383 at the start of it I would say it was cast after 1975 so it is probably the intake that came with the heads.