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2 bbl to 4bbl swap - now what fuel pump?

what fuel pump

  • Mr. Gasket OEM 35 GPH 4-7psi

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barbiebandit

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I'm a backyard mechanic that can change oil, brakes, alternator...basically I know how to turn a bolt, but am a newbie to the intricacies of optimizing combustion and tuning. TLDR: dumb it down for me.

74 satellite RR clone...my first mopar adventure.
Has '66 383 in it mated to 727 auto 3sp and B&M shift kit

Had the original intake and 2bbl carb on it. Ran fine, but I wanted more. Also, the engine looked completely stock except for some chrome valve covers. When I removed the current stock intake and carb, it still had the factory insulation there...so I bet the original cam is still in the motor and it hasn't even been apart.

So I found a cheap craigslist deal ($200):
Edelbrooke 383 Torker Intake with a 4bbl holley carb with electric choke. Numbers are :
8051B and 80508-3 (and 2765 is the date code)
According to Google This is apparently a 750cfm dual feed 4160.

It does not have a ported vacuum (no nipple for the hose anyway). so manifold vacuum only. I also have a non adjustable vacuum advance can on the car.

So after doing the intake and carb swap it bugs when I apply the gas (in gear - in neutral it revs and sounds boss). But in gear below 30 MPH it tries to stall unless I give it a feather touch on the gas, especially from a full stop. over 30 MPH it doesn't try to stall or bog, but has no guts...I can slowly bring it up to enough speed to bury the needle on the hwy, but if I am doing like 50 MPh and tromp on the gas, it just slowly increases speed..no downshift.

the questions:

I was told the fuel pump probably is not great (there is a sub 5 psi on the dual fuel feed gauge) and should be changed as it probably can't keep up with the fuel demands of the new setup.

Do you agree?

What fuel pump should I get?

I had my local parts supplier look up a 71 roadrunner (since that had a 383) for compatible fuel pumps.

There is a holley model 12-440-11 which delivers 110GPH with 6.5 to 8psi available... is this too much psi and cause the float to not seat properly and flood my engine?

Or there is an OEM type from Mr. Gasket (part no. 12S) putting out 4-7 psi and 35 GPH.

Also, Should I plug my non vacuum advance into my manifold vacuum? I was told to try and get a nipple for where the ported vacuum should be but I wonder if the porting in the carb is even in there. right now I don't have the plugged into any vacuum.

Also, any issue with the originL cam in there with this setup? I really hope not.

My plan is to do the fuel pump and see if that helps. if not, I will have to bring it to a performance tuning shop since I don't know enough of the rocket science behind it all but rather see what I can before though.
 
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Don't see fuel pump as an issue. Carb probably not setup correctly. Manifold vacuum on your advance will open a can of opinion worms, but manifold vacuum is fine.
 
Make sure your kickdown linkage is adjusted properly. Very important! Your low speed bog could be an accelerator pump issue. I'm sure that carb would have ported vacuum advance. Nipple fell out? If it is there, either plug it or use it.
 
Sounds like your kickdown (no down shift below 30 or 50mph) is not adjusted right to start with make sure you get that done. The other thing is how old is that carb and how long has it been sitting? No kickdown and to much fuel can cause the bog. Make sure your accelerator pump is functioning. Proper timing, carb tuning, and linkage adjustments after and manifold/carb swap.
 
First things first! You put a single plane intake on a stock motor? You'd be better off with a dual plane and a 750. Your running a dual feed as well, I bet that those are your 2 biggest problems right now, as they're probably to much for what you have. Good Luck
 
Carter makes a good mechanical pump for your application. The Holley is overkill for a stock 383. MO

https://www.summitracing.com/parts/crt-m6903/overview/make/chrysler

CRT-M6903_PV_ml.jpg
 
Dual plane and a 500 cfm or 625. The kickdown linkage rod (horizontal one at the carb) should touch the throttle shaft extension when the throttle is closed.
Make sure it is connected all the way down to the transmission.
 
Don't see fuel pump as an issue. Carb probably not setup correctly. Manifold vacuum on your advance will open a can of opinion worms, but manifold vacuum is fine.
Thanks I plugged my advance into the manifold vacuum. Seems to run better
 
Make sure your kickdown linkage is adjusted properly. Very important! Your low speed bog could be an accelerator pump issue. I'm sure that carb would have ported vacuum advance. Nipple fell out? If it is there, either plug it or use it.
Apparently the older version of this carb didnt have it. I talked to a mopar guy at the local car show that never seen a nipple for the ported vacuum...just manifold. anyway, I plugged it into manifold and it seems to run better. he said the same as you about the kick down ...said I can blow out the seal in my tranny if I bog it!
 
Sounds like your kickdown (no down shift below 30 or 50mph) is not adjusted right to start with make sure you get that done. The other thing is how old is that carb and how long has it been sitting? No kickdown and to much fuel can cause the bog. Make sure your accelerator pump is functioning. Proper timing, carb tuning, and linkage adjustments after and manifold/carb swap.
Thanks! seems my carb is definitely not set up right. "accelerator pump"? I have to look that one up. the carb and intake came as a unit and are definitely old but look relatively cleaner at a vintage car show i got the name of a tuner that does performance carb setups and will likely hire this out as there seems to be too many variables and dickering ... it would take me an age of hit and miss to get it.
 
First things first! You put a single plane intake on a stock motor? You'd be better off with a dual plane and a 750. Your running a dual feed as well, I bet that those are your 2 biggest problems right now, as they're probably to much for what you have. Good Luck
Yes it was $200 for both so I decided to roll the dice. I will take this franken-mess to a local mopar performance guy who will either set it up right or possibly also tell me I went overkill. I hope he can make it work!
 
Dual plane and a 500 cfm or 625. The kickdown linkage rod (horizontal one at the carb) should touch the throttle shaft extension when the throttle is closed.
Make sure it is connected all the way down to the transmission.
Thanks I am going to bandaid the kickdown with a spacer bolt in the linkage rod you mentioned until I bring it for a pro carb setup....but that will help me not bog it in interrim
 
You can shift it manually as well, just does not work quite as well.
 
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