1971 383 4 barrel carb.

[71Charger500]

Is it true that in 71 the 383 4 barrel in the Charger 500 was bumped down from 335 to 300 horse?  If so, could someone explain to me how I would going about rasing the compression ratio to add more horse on...I just got this car, and am kind of new to this whole thing.

[Chryco Psycho]

the only ways to increase compression are
1] change the pistons ,
2] use closed chamber heads ,
3 have the block or heads milled dowm
4] use a thinner head gasket

[max]

just my opinon, but if it is going to be a street only use then i would leave the compression alone unless the engine needed rebuilt then maybe i would change it to a slighty higher true compression but then i wouldn't go for anything over 10.1.

i'm thinking the advertised compression was 9.1 on that year so it would still work fine with todays gasoline. you have to remember gas is only getting worse instead of better.

i would look into a better cam and intake/crab to gain the few extra hp that you are looking for if your engine doesn't need a rebuild.

[cudaken]

 My self, I would not worry about what the books say the HP is. Truth is Maw Mopar lied alot about there ratings.

Make sure what you have is making all the HP it should. Make sure your distributor is getting full advances and is working right (have a speed shop set it up) and carb is tuned right and getting Wide Open Throttel when you drop the hammer (seen more than one that was not). Chassie Dyno run is the best way to have the Car set up. Be there is 25-35 HP yet to be found if not tuned by a real pro.

If I where you, if you do anything to the 383 have machine shop check push rod length. Most Big Block Mopars deck's where to tall, stock push rod will not open the valve to it max if deck height is off.

                      Cuda Ken