Which distributor for 383 ?

[sanders7981]

Now that my engine is built, I need to get a carb and good distributor.  Has anyone used an AED 750 carb?  According to my builder, my engine should make about 450 hp.  Also, I'm leaning toward an MSD distributor.... Unless there's something better out there bang for buck wise.  Suggestions? 

[Nacho-RT74]

Check for firecore distribuitors. Stockish look but better built

[firefighter3931]

I like the Proform street series carbs ; nice features and easy to tune. They are also available with an electric choke. 

As Natcho mentioned, the FireCore distributors are excellent quality and value. There are two models available for the lowdeck 383/400. The Chrysler electronic looks like the factory piece and comes with vacuum advance. The Billet mechanical looks similar to the MSD pro-billet and does not have a vacuum advance pod. Both are hundreds cheaper than the comparable MSD version.

I've sold hundreds to the members here over the years with excellent results. 

FireCore also has the finest ignition wires for sale that are configured for Mopar applications. They come in 2 versions :

(1) Factory fit = stock exhaust manifolds
(2) Pro fit = aftermarket headers

These wiresets are a true plug & play = no cutting/crimping and they use premium double crimped brass terminals and silicone boots.



Ron

[Nacho-RT74]

Ron, I don't remember if I asked this before, but would like to know the interior of the firecore dist... whats the diff between these and stock units ?

I know they use the stock pick up coil which is an advantage for replacement parts ( I think the stock cap is a direct replacement too ), but how is the vacuum advance plate, the mechanical advance system, and if they run in bearings or bushing ?

IMHO the bigger disadvantage of the stock dist is the play the vacuum advance plate got, what is able to bite the reluctor if adjusted too close, and depending on the pick-up coil bracket shape, since it moves on a diff center ratio than the reluctor circunference. The shape of the pick-up coil bracket can get it way closer or way farther to the reluctor when vacuum works. I have play a lot with this, bending the coil bracket to get the gap the most similar as posible with and without vacuum ( between .008 and 010 )

then the second weak point is the brass bushing which is not a real problem on small blocks, but it does on Big blocks due the angled position, adding friction by the shaft assembly weight, getting it worn faster

sorry if this is a highjack.

[sanders7981]

No worries Nacho!  I haven't messed with anything distributor wise on an old car in probably 18 years.  I'm re learning as I go. 

[firefighter3931]

Hi Natcho 

I'll try to answer your questions ;

The FireCore distributors are dimensionally the same as a stock distributor but with significant improvements. The housing is billet aluminum and the shaft support is a rollerized bearing as opposed to the OEM style bushing. This translates into rock solid timing to 8000+ rpm. No more spark bounce when trying to time your engine. 

The cap is available in stock tan or male post HEI style. The mechanical advance is infinitely adjustable and takes just a few seconds using a screwdriver. Makes for much easier tuning. The distributor also comes with an advance spring kit to custom tailor the curve for your application. 

*I have advance spring charts available for those who wish to supertune their timing curves 

The FC distributor also uses a stock reluctor and pickup. I have not seen any issues with vacuum advance adjustments causing interference with the pickup assembly as long as the reluctor gap is properly set @ .008-.010 but I do recommend using a dab of blue locktite on the pickup screws to keep everything tight inside.



Ron

[68Charger4me]

I'd like that chart please!

[firefighter3931]

Sure, send me a PM with your e-mail address and i'll fire off the PDF's 

Which FC distributor do you have and what springs are currently installed ? 

Many are leaving power & throttle response on the table with lazy timing curves and (too) modest base timing. BB mopars respond well to increased spark lead @ idle and a quick curve. 



Ron

[Nacho-RT74]

I have not seen any issues with vacuum advance adjustments causing interference with the pickup assembly as long as the reluctor gap is properly set @ .008-.010 but I do recommend using a dab of blue locktite on the pickup screws to keep everything tight inside.



Ron

yeah, well, on the stock distribuitor, the floating plate system for the vacuum advance is really a problem. ASIDE the default failure on the way it moves on a diff circunference than the reluctor, able to not get a parallel circunference and keep the same gap all allong the advance, the free play on the moving plate assembly is able to move way more the pick up coil assembly until REALLY bite the reluctor. This is also even worst on BB due the dist position, ( same case to the brass bushing ).

I'm really courious about this on the FC unit.

I have allways get a jumping initial time trying to set it it. Never have being able to get it steady at whatever initial timming I set ( using "at this moment" the MP "mallory" unit )

[68Charger4me]

Sure, send me a PM with your e-mail address and i'll fire off the PDF's 

Which FC distributor do you have and what springs are currently installed ? 

Many are leaving power & throttle response on the table with lazy timing curves and (too) modest base timing. BB mopars respond well to increased spark lead @ idle and a quick curve. 



Ron

Thanks Ron, I have the firecore vacuum advance distributor with an Accell digital 300 box, running the springs that were installed from new.  451 stroker,830 quickfuel dp, 19 initial, 34 total.  Muscle motors had it locked out at 33 total when I got the motor, but it was hard to start..

[firefighter3931]

Sure, send me a PM with your e-mail address and i'll fire off the PDF's 

Which FC distributor do you have and what springs are currently installed ? 

Many are leaving power & throttle response on the table with lazy timing curves and (too) modest base timing. BB mopars respond well to increased spark lead @ idle and a quick curve. 



Ron

Thanks Ron, I have the firecore vacuum advance distributor with an Accell digital 300 box, running the springs that were installed from new.  451 stroker,830 quickfuel dp, 19 initial, 34 total.  Muscle motors had it locked out at 33 total when I got the motor, but it was hard to start..

I got your PM and e-mailed the advance charts 

What cam, compression and cylinder head ? Big cams like spark lead and you can pick up some idle vacuum with proper distributor tuning. Some will kick back/turn over slowly if the distributor is locked out so a short mechanical curve will often work better.....which seems to be the case in your situation.

It's a matter of dialing in the best base timing and limiting the total to where it needs to be while adjusting for the quickest curve that the engine combination will tolerate without detonating. The closed chamber aluminum head builds run best at 34-36* total with a quick curve, from my experience. 



Ron


Ps. Apologies to Sanders....we've turned his distributor search thread into a distributor tuning tutorial 

[68Charger4me]

Yup, sorry bout that, should have started a new thread lol..
Comp cams 284/296 507/510, 10.1 cr, I believe they're sidewinder aluminum heads.. 
again sorry about the thread jacking!   

[firefighter3931]

Yup, sorry bout that, should have started a new thread lol..
Comp cams 284/296 507/510, 10.1 cr, I believe they're sidewinder aluminum heads.. 
again sorry about the thread jacking!   

Based on that engine combination I would recommend going with a pair of silver springs. That will speed the curve and sharpen throttle response. 

Next I would limit mechanical advance to 10* thus allowing you to bump the base timing up to 24-25* at idle. To do this you will have to close the limiter window down to 2/3 closed. The mechanical advance mechanism has a total of 30* of adjustment so exposing 1/3 of the travel will yield 10* of mechanical advance. 

Let us know how it's running afterwards 



Ron

[68Charger4me]

Yup, sorry bout that, should have started a new thread lol..
Comp cams 284/296 507/510, 10.1 cr, I believe they're sidewinder aluminum heads.. 
again sorry about the thread jacking!   

Based on that engine combination I would recommend going with a pair of silver springs. That will speed the curve and sharpen throttle response. 

Next I would limit mechanical advance to 10* thus allowing you to bump the base timing up to 24-25* at idle. To do this you will have to close the limiter window down to 2/3 closed. The mechanical advance mechanism has a total of 30* of adjustment so exposing 1/3 of the travel will yield 10* of mechanical advance. 

Let us know how it's running afterwards 



Ron

Ok, so close down both windows 2/3, I'll do that this weekend, thanks Ron, your a great asset to this site!!

[firefighter3931]

Ok, so close down both windows 2/3, I'll do that this weekend, thanks Ron, your a great asset to this site!!

Yep, just leave 1/3 of the window exposed.....that'll give you 10* of mechanical advance.   

You will have to loosen both screws and both of the tabs will move together as they are attached on the same floating plate. Once you move one of the adjustable stops you will notice that the other is moving as well. This will be obvious once you start adjusting the mechanical advance mechanism. 

The increased base timing from 19* to 25* will increase your idle speed and manifold vacuum so you will have to adjust the idle speed on your carb after making this timing change. 

The increased base timing along with the quicker curve using the silver springs will make the engine snappier off idle improving throttle response. 



Ron

[68Charger4me]

Ok, so close down both windows 2/3, I'll do that this weekend, thanks Ron, your a great asset to this site!!



Yep, just leave 1/3 of the window exposed.....that'll give you 10* of mechanical advance.  

You will have to loosen both screws and both of the tabs will move together as they are attached on the same floating plate. Once you move one of the adjustable stops you will notice that the other is moving as well. This will be obvious once you start adjusting the mechanical advance mechanism.  

The increased base timing from 19* to 25* will increase your idle speed and manifold vacuum so you will have to adjust the idle speed on your carb after making this timing change.  

The increased base timing along with the quicker curve using the silver springs will make the engine snappier off idle improving throttle response.  :
Ron

Thanks, I'm going to try this this weekend

[68Charger4me]

Wow, it is snappier off idle, it was good before, but now its immediate!  25 base, 36 total. No bucking to start at all.  Thanks again Ron!

[firefighter3931]

Wow, it is snappier off idle, it was good before, but now its immediate!  25 base, 36 total. No bucking to start at all.  Thanks again Ron!

Nice work ! 

Glad to hear it's running/performing much better.....amazing what a little tuning will accomplish ! 



Ron

[69wannabe]

That's alot of base timing but if it starts good then that's awesome. Bet it is very responsive with the timing set there. I have got the firecore plug and play distributor and wire set with a MSD blaster 2 coil and resistor and a mopar chrome box and it all works great together. Got my timing at 18 initial and 34 total with cast iron heads. Got some stealth heads ordered and having them prepped by La Roy engines and not to hijack the thread but would I need do any changes to my timing once I get the heads swapped out. Got a 493 ci RB engine, 10 to 1 with the 284 XE comp cam and a 850 holley double pump carb. I was thinking with the iron heads gone I may could get a little more timing out if it. Mine is street driven and the advance curve in the distributor seems to be great for my type of driving but I am open for suggestions.....

[68Charger4me]

I was leery at first of that much base timing too at first, but there is no difference in starting it at all, the throttle response is much more noticeable, it used to feel a little  lazy around 30 mph or so, but not anymore.