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42 to 44 is to much total for a big block mopar. 36 to 38 tops.

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FWIW...my 383 was doggy with the big open chamber 906 heads. With a set of 516s on her now she is a totally different animal and she is running the .474 cam. It DEFINITELY puts you in your seat and will annihilate the tires from a stop.

So my says that you may be very low on compression and that is really all you need to work on.

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My reply for 42-44 is for a car with low comp and too much cam like the 509 Too many people go by the Mopar perf bible that are often way out of date.I had a Mopar perf tech guy tell me a 509 would be ok in a small block with exhaust manifolds NOT. Now I do my own thing and if it works for me so be it.

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Paul, you're right. Them little guys need timing. It is NOT a 440.

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FWIW...my 383 was doggy with the big open chamber 906 heads. With a set of 516s on her now she is a totally different animal and she is running the .474 cam. It DEFINITELY puts you in your seat and will annihilate the tires from a stop.

So my says that you may be very low on compression and that is really all you need to work on.

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stock pistons ?

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So i ended up just popping the distributor out and i looked under the plate and realized one of the advance springs was missing! The remaining spring was the lighter of the factory installed springs. I ended up putting BOTH Mopar perf. Light springs in and stabbed the dist. back in where it was. I had no way to check timing but i did notice when i fired the motor up my rpms went from a previous 700rpm at idle to now 1k at idle,and a noticeabley smoother idle/power.

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Here's a chart. I hear MSD make dialbacks act up. you could do a slight bit of math and mark the dampener exactly. .0632683" is 1 degree so 35.5 degrees would be 2.246 (2&1/4") and you could use your 2-3" micrometer and measure/cut strips of paper to use as a ruler & magic mark your dampener & you can mark 5 deg on the stock marks then move the dampener 5 degrees and mark it again & so on until you've got up to 35 40 btdc and checking for exact TDC with the ten dollar tool is a good idea as you cannot assume anything then use a non dialback light. EDIT forgot the chart

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FWIW...my 383 was doggy with the big open chamber 906 heads. With a set of 516s on her now she is a totally different animal and she is running the .474 cam. It DEFINITELY puts you in your seat and will annihilate the tires from a stop.

So my says that you may be very low on compression and that is really all you need to work on.

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stock pistons ?

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No it has been rebuilt. the problem with the first build and the 906 heads was the KB162 pistons which are something like a mile in the hole with huge 5cc valve reliefs. My compression on the first build was around 7.8:1.

Now it has the same pistons, but the deck was milled 0.020 and with the 516 heads and the felpro gasket i get a CR of 9.2:1 which really woke the motor up.

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42 to 44 is to much total for a big block mopar. 36 to 38 tops.

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Hey 71383bee,

How do you like that .474/.474 MP cam?

I'm looking at a build for the 383 in my 71'bird and I think we talked a couple times before. Comp cams camquest version of this MP cam gives my 383 the max hp and torque and should work well with my 4 speed and AC.

What gears and transmission are you running? Hi-po manifolds or headers?

Don't mean to hijack the thread, just not alot of guys who drive the 383 as much as 440's, or the MP cams since they are "old technology".

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I am very happy with it. It has got excellent street manners and can bring it when it needs to. The motor dyno'd at 400/430 hp/tq which was my goal.

Its a pretty mild build really...040 over on the bores, KB162 pistons, mill the deck 020, built 516 heads with the 2.14/1.74 valves IIRC and a bit of bowl blend and porting, Comps 474 version (nostalgia purple plus) cam, street dominator intake, FBO prepped 650 mighty Demon, and the FBO ignition.

Haven't tried it at the track. Running a 727 auto with the TF2 shift improver kit and 3.73 gears. I prefer to slapstick it. From a stop first gear is virtually useless with the tires I have, but its a fun cruiser! There certainly is faster out there, but she holds her own pretty well. I can drive it anywhere and she holds an idle very well with power brakes.

I have been following your thread too. FWIW i would just try and coax 400 to 450 hp from your stock 383 and keep it mostly stock appearing. Unless you already have the 440 that is. I do have to agree that as much fun as having an absolute killer 500 hp motor is it does eat in to how much you really can use the car. Especially it being a fairly rare real 4 speed high impact bird. 400 hp is still a lot of fun and it has good street manners means IMHO that you can do more with the car. I have several friends that have invested so much into there cars that they are no longer as tame for taking on nice cruises or going to a long distance show. they kill at the strip which is cool, but they sometimes miss out on just cruising the backroads and raising a bit of he[[! A 400 to 450 hp mill will still be respectable at the strip and you won;t have to modify the car much to handle it. Anyways thats just my