A few general questions about my 383 Magnum

[Iron Chef]

I have a 1971 Super Bee with a 1966 383 Magnum.  I'm looking to keep it mostly stock but have good streetability and performance, so I'd like to find out a few things:

1) What kind of carb was supposed to come on that engine from the factory (manual transmission).  It currently has an Edelbrock 750CFM Carb on it.  Is this a decent carb or can I do better.

2) It's on an Offenhauser manifold.  Again...opinions?  Are there better options out there?

3) On a power brake car, where did they typically take manifold vacuum from, the manifold or the back of the carb?

4) Cold starts: I have to crank it a lot to cold start it.  Is there a better way?

5) Right now I'm using a "six pack style" air cleaner assembly that's been modified for a four barrel (kinda looks like the air grabber without the hood hardware).  Is there anything wrong with using the factory dual snorkel model?

Thanks for any and all help/suggestions. 

[Morten Andre]

I had an Offenhauser dual port 360 on my 440cid.
Changed it out for an Edelbrock CH4B and noticed a big improvement in performance!
I think it is designed as a gas saving manifold. But very interesting design with those dual runners.
Each port has one runner connected to the primaries and one runner connected to the secondaries.
I cannot care less about fuel milage, because this car is a hobby for me. It sees very few highway miles and
deserves every gallon of fuel it can burn.
About the vacuum it will be the same if you connect to the carb or on the manifold.
If you are cranking a lot to get it to start there could be something wrong with the choke.
But my 440 does not have a carb with choke and starts right up after three pumps on the throttle even at 14 Fahrenheit!
Of course it does not idle before it has warmed up so I hold a my foot a tad on the throttle. 

Best regards
Morten André

[frederick]

1) The Edelbrock 750 is generally regarded as the problem carb.
Loads have trouble tuning an off idle stumble.
But if your's is fine I wouldn't swop it.

Here's a test with different carbs;
(Edelbrock 750 doesn't do well)
http://www.moparts.org/Tech/Archive/bb/25.html
http://www.moparts.org/Tech/Archive/bb/26.html


2) It's on an Offenhauser manifold.  Again...opinions?  Are there better options out there?
If you've got space beneath the hood, the Edelbrock RPM is the one to have.
http://www.hotrod.com/techarticles/hrdp_0712_mopar_intake_manifold_comparo/index.html


4) Cold starts: I have to crank it a lot to cold start it.  Is there a better way?
Most likely the fuel has boiled out.
This is common with Edelbrock carburettors, easiest remedy is install a phenolic spacer.
eg:
http://cgi.ebay.com/ebaymotors/1-PHENOLIC-HOLLEY-4-BARREL-CARBURETOR-SPACER_W0QQcmdZViewItemQQhashZitem4839bc9bafQQitemZ310206307247QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

Make sure the hood still closes, it raises the carburettor one inch.



Cheers,

Frederick

[Iron Chef]

Thanks guys.  GREAT info and much appreciated!  I'll be putting these suggestions into play! 

[femtnmax]

A friend has the dual port Offy on his 440.   That thing needs the carb jetting to be set very rich to run ok.  IMO you would be better off with most any other intake manifold, even a stock cast iron would be better.  The aluminum intakes heat up and cool down faster than cast iron, so if your in cold country maybe cast iron would be easier to drive.   On the other hand as mentioned the Edy Perf RPM has a great performance record for street use.

[71383bee]

I agree...ditch that offy.  At a minimum you can get the vanilla performer intake which is basically an aluminum version of the stock casting.

I like the RPM and am running a Holley Street Dominator now...VERY happy with it. 

[Iron Chef]

Yeah...I think that the Offy and the Edelbrock carb are going in favor of an Edelbrock manifold and Holley Street Dominator.  I know this motor can do better with minor tweaks.

I've since found out that I have a pre-1970 8 3/4 rearend.  Getting 3.23's for this is going to be tough. 

[Nacho-RT74]

I agree...ditch that offy.  At a minimum you can get the vanilla performer intake which is basically an aluminum version of the stock casting.

so in your opinion the basic performer is better than the offy ?

[71383bee]

I agree...ditch that offy.  At a minimum you can get the vanilla performer intake which is basically an aluminum version of the stock casting.

so in your opinion the basic performer is better than the offy ?

Yes.  At least the offy he is using.  I like CH4b too...