1969 383 4 barrel vs 1971 383 2 barrel

[70 sublime]

My car was born with a 1969 383 4 barrel motor that is long gone
I have found and installed a 1971 383 2 barrel motor

What is the difference in the two motors and what parts would I need to change to make the 71 motor have the same HP as the 69 would have had ??

Looking up what I can find I came across this listing

Chrysler Corporation Engine Specifications (1966 to 1974 engines)


1969 383 4 barrel

   330 Horsepower. V8-383   4 Barrel   4.25 x 3.38   383   10   330 @ 5000   425 @ 3200
   
1971 383 2 barrel

   275 Horsepower. V8-383   2 Barrel   4.25 x 3.38   383   8.5   275 @ 4400   375 @ 2800

Also lists the 1971 4 barrel version

   300 Horsepower. V8-383   4 Barrel   4.25 x 3.38   383   8.5   300 @ 4800   410 @ 3400


How do they get the higher compression in the older motor ?
Different pistons or heads or both ?

The 1971 2 vs 4 barrel was it just an intake and carb change ?

If I can just swap the intake and a 4 barrel carb onto my motor and get 300 HP is it even worth trying to get the extra 30 to get to 330 HP ?   

[c00nhunterjoe]

Pistons, cams, intakes, and obviously the carbs.. 50 yrs later you have no idea what heads might have been swapped.

[ACUDANUT]

  "I have found and installed a 1971 383 2 barrel motor". I am guessing it was rebuilt at one time ?
I sure hope so.     I wonder why a Big Block motor ever came with a 2 Barrel carb. 

[70 sublime]

  "I have found and installed a 1971 383 2 barrel motor". I am guessing it was rebuilt at one time ?
I sure hope so.     I wonder why a Big Block motor ever came with a 2 Barrel carb. 

My 383 came out of a four door Chrysler Newport
Ran like a top and the previous owner drove the car to my place after I bought it
No air conditioning or anything extra on the car other than power steering and power brakes
Motor does not appear to have ever been rebuilt as how much grease and grim was on it
Car was low mileage car with about 50 000 miles on it ( interior and seats looked good so it did not have 150 000 on it )

[firefighter3931]

The 383 2V had a lower compression ratio, milder cam, log exhaust manifolds, 2bbl carb/intake.

To wake that puppy up you'll need to increase the static compression ratio, install a good cam, intake, 4bbl carb, headers and possibly a set of closed chamber aluminum heads.

Assuming the bottom end is in good shape and it really is a low mile (50K) shortblock you can get away with simple boltons.

This engine is a good candidate for a set of 75cc E-street cylinder heads.



Ron

[John_Kunkel]

Also, a '71 383-2 from an automatic car likely has a cast crank.

[375instroke]

At least in '69, a 2V 383 had the same cam as a 4V 383.  Only the Roadrunner and Super Bee had the larger cam.