Difference between older 440 engines and newer 440 engines?
 

I have a '77 440 Chrysler engine. I have heard that the older 440 engines (1965-1971) performed better than the later 440 engines (1972-1978). What's the difference between the new and old ones. And can I make mine perform just as good as the older ones and how? Also, I know that the "thinwall blocks" on the later 440s is a myth. Thanks.

Welcome.

Compression, Camshaft, Carburetion.

Increase these and you will travel back in time.

Stay in this time with much better camshaft and carburetor design or add EFI and make it perform better than the "old ones".

All a myth for the most part.... Get a good Mopar Builder on your team.... Just my 2 cents.. :)

What are you looking to build... Street or Race Motor?

Tom -

Depends on how you define "engine".
The later blocks (late 70's) were actually the strongest physical blocks Chrysler made, since they were intended for motor homes and trucks. Like Coronet said, the stuff they filled those blocks with were low performance "smog" components. The turning point there was 1972 when the smog restrictions came into play.

If your building a motor look for a forged crank and good rods and everything else will be after market.

BUT, like Bob said, you first have to decide if you're looking for a race or a street motor. While not mutually exclusive, most race motors aren't happy on the street (as in traffic), even though their owners will tell you they are, and most street comfy motors don't turn in top times.

Archer

I want it a street motor but still have a good amount of hp like around 400hp. My brother has a '74 Challenger with a '67 440 that has around 375 hp so I want to have a little more than him. Planning on putting it in a '68 Charger.

The one thing that will hold any of these post '71 engines back is cylinder heads.

Here is a good read. http://www.dodgecharger.com/forum/in...topic=104749.0

Well Then... Coronet 500 Dan is giving you great advise...
Head swap, add some compression, a good cam, a good intake carb combo, and you are set for flight.... :)

The 76-78 heads flow better than the 906 and 915s to .560 lift.

Check your head casting number, likely 452. Lots of good info if you search or get one of the Big Block HP modification books.

http://www.moparts.org/Tech/Archive/bb/62.html

Need to decide how much you want and if you need head swap or DIY porting or new aluminum HP heads.

Always got to start with an honest assessment of end usage.