The classic "What carb?" question: relatively stock but healthy 440

[theseoldcars]

Hello everyone! My name's Lewis and I've got a '68 Charger with a 440 in it, and I was looking for a little advice regarding carburetor choice. I've trawled the forum and read so many posts that I've lost track, but I'd loathe to make the wrong choice.

When I bought the Charger I was told it had a 650cfm vacuum secondary Holley on it, which sounded a little small to me. Nevertheless, it seemed to move out pretty well and drove in a crisp, clean fashion - although at idle it smells a little rich.

However, on closer inspection, I found out that the carb was actually a 600cfm item (an 1850-3). Consequently I feel like I'm possibly leaving a lot on the table in terms of performance.

My 440's relatively standard, however. It's got a CH4B intake on it, a set of headers (think they're 1.75" ones), an old aftermarket exhaust, decent leads and plugs, and an MSD coil. The rest is, as far as I'm aware, as it left the factory. I think the 440's a '72 - my car was originally a 383. It's still backed by a 727, however.

Is it worth moving up to something bigger? I tend to just cruise around but I do make the odd visit to the drags and I want it to perform as well as it can. I've been very tempted by the likes of the Holley 4150 HP carburetors but the Quick Fuel Slayer (in 750cfm vacuum secondary configuration) also appeals - plus it's not silly money.

I've also bought a decent phenolic four-hole spacer, a heat shield plate and have a Quick Fuel pressure regulator and a new fuel filter assembly to go on, too, to complete the setup. The only missing piece otherwise is a suitable air filter assembly, as I'm not sure how much hood clearance I've got.

Thanks for all your help, in advance. Here's a shot of the car as it stands. It's been in the UK since '79, so it's doing well to have survived our climate that long!

[rt green]

the tried and true holley 750 3310 works well.

[b5blue]

   I just installed a Pro Form 750 with vacuum sec. on a CH4B. With a 1/2 spacer, a 71 type 440 air cleaner fit with decent clearance on my 70 Charger. I used a 4BBL aftermarket throttle bracket that sits a bit higher and just barely reached for kickdown adjustment. I've not gotten the dual feed fuel lines worked out yet but will end up fabricating something more correct later.  It's worked out well and fairly simple.

[Ghoste]

Yep, to both.  3310 for the least expense and the upgrade version for a little more.

[tan top]

 hello & welcome   

[303 Mopar]

I recently added a CH4B intake and Proform 750 carb to my 440 and made a big difference from my 600 carb.  I also added a 3/8" mainline and kept the original 1/4" line as my return line now.  I was having fuel evaporation problems so ended up routing the line from my mechanical pump to a filter on the inner fender and then over to the carb and wrapped it to avoid as much heat as possible.  You might want to consider upgrading your distributor to a Firecore as well.  Ron Wilson on here can give you all the detail you need, great guy!

[c00nhunterjoe]

It sounds like a bone stock low compression 440 with an intake and headers. If so, going from the 600 to a 750 might net 8 hp after you have retuned it. Even 10hp on a 2 ton car wont feel different on the street. If you are not changing anything else, i wouldnt worry about an upgrade right now.

[firefighter3931]

Welcome Lewis....nice looking 68 ! 

A 600 cfm carb is small on a stock 440 and yours has a better intake manifold and headers/performance exhaust. That being said, the engine is much better vs a bone stock 440 with factory intake and exhaust manifolds. For sure it would benefit from a bigger carb to match the other bolt ons. 

I like the ProForm street series carburators on mild builds. A 750 cfm with electric choke like the one on Dan's 440 would be a step in the right direction. Tuning the timing and advance curve will also make a big difference in performance and throttle response. 


Ron

[theseoldcars]

Yep, to both.  3310 for the least expense and the upgrade version for a little more.

   I just installed a Pro Form 750 with vacuum sec. on a CH4B.

the tried and true holley 750 3310 works well.

Seems to be a theme! Many thanks for the feedback, really appreciated. Sounds like a 750cfm would be a good choice. Happy New Year to you all!

[theseoldcars]

hello & welcome   

Greetings tan top!

[theseoldcars]

I recently added a CH4B intake and Proform 750 carb to my 440 and made a big difference from my 600 carb.

Thanks, 303 Mopar. That looks really clean. Very nicely done. I'll definitely think about the distributor; mine's an original item and has a little play in it, but otherwise works well and it's backed by fresh points, a new cap and rotor, new leads, an MSD coil and suitable NGK plugs. I would like to upgrade it, though, so I'll have a good look at the Firecore option. Cheers!

[theseoldcars]

It sounds like a bone stock low compression 440 with an intake and headers. If so, going from the 600 to a 750 might net 8 hp after you have retuned it. Even 10hp on a 2 ton car wont feel different on the street. If you are not changing anything else, i wouldnt worry about an upgrade right now.

A very valid point, no doubt! I'm going to be rebuilding the 600cfm Holley this weekend and putting on my other new bits, so I'll see how it feels then. I do intend to get it rolling roaded soon, so I can see if there's anything amiss and exactly what it's doing, then I'll go from there.

[theseoldcars]

Welcome Lewis....nice looking 68 ! 

A 600 cfm carb is small on a stock 440 and yours has a better intake manifold and headers/performance exhaust. That being said, the engine is much better vs a bone stock 440 with factory intake and exhaust manifolds. For sure it would benefit from a bigger carb to match the other bolt ons. 

I like the ProForm street series carburators on mild builds. A 750 cfm with electric choke like the one on Dan's 440 would be a step in the right direction. Tuning the timing and advance curve will also make a big difference in performance and throttle response. 

Ron

Thanks Ron! Thanks for the welcome. Cheers! It'd been parked in a garage for a decade so it's taken a bit of work to get it back on the road (new brakes, boot floor, complete service, new upper arms, etc), but it drives very sweetly so it was well worth putting the effort in.

The ProForm street carbs look ace. I'll have a good read of the spec sheets and put those on the Summit Wish List! Ignition timing and tuning is on the list, as is a new distributor, methinks.

A belated Happy New Year to you!

[b5blue]

  Ron steered me to the P/F 750 and it's close out of the box. The Firecore Dizzy (I use the RTR.) has run flawless. I fed both the RTR (No resistor, full 12V coil.) and the P/F 750's electric choke with control relays that turn off and on using start/run (Tied together.) ignition and tap black main ALT. output to supply both (Each separately fused.) mounted on the engine bay firewall.
  I get no voltage drop feeding ether this way and actually reduce current load into and out of the dash/interior/ignition switch/bulkhead connector. The car can sit for a week and still fires right up. I also upgraded to the HP fuel pump from Mancini but I don't think it's necessary.   
  THANKS again Ron!
 

[Ghoste]

I'll add my welcome to the site too.  Are you in the UK?

[myk]

For the dual inlet carb users, what dual inlet line did you use?  I keep reading that not many of those preformed lines fit very well...

[Ghoste]

I have used a Mr. Gasket (IIRC) that worked and a Holley one.

[b5blue]

For the dual inlet carb users, what dual inlet line did you use?  I keep reading that not many of those preformed lines fit very well...

None work out like I'd like, I'll end up fabricating something stock-ish looking now that the guy who use to make them had to quit.

[theseoldcars]

  Ron steered me to the P/F 750 and it's close out of the box. The Firecore Dizzy (I use the RTR.) has run flawless. I fed both the RTR (No resistor, full 12V coil.) and the P/F 750's electric choke with control relays that turn off and on using start/run (Tied together.) ignition and tap black main ALT. output to supply both (Each separately fused.) mounted on the engine bay firewall.
  I get no voltage drop feeding ether this way and actually reduce current load into and out of the dash/interior/ignition switch/bulkhead connector. The car can sit for a week and still fires right up. I also upgraded to the HP fuel pump from Mancini but I don't think it's necessary.   
  THANKS again Ron!
 

Thanks for the heads-up Ron. Sounds like it'd be a great combo. I intend to use the car a lot once I've dialed out a few gremlins (leaky trans pan, got a new one to replace it, and so on), so a decent turn-key setup that runs like that would be ideal.

[ACUDANUT]

I recently added a CH4B intake and Proform 750 carb to my 440 and made a big difference from my 600 carb.  I also added a 3/8" mainline and kept the original 1/4" line as my return line now.  I was having fuel evaporation problems so ended up routing the line from my mechanical pump to a filter on the inner fender and then over to the carb and wrapped it to avoid as much heat as possible.  You might want to consider upgrading your distributor to a Firecore as well.  Ron Wilson on here can give you all the detail you need, great guy!

Holley 750. No return needed.

[303 Mopar]

For the dual inlet carb users, what dual inlet line did you use?  I keep reading that not many of those preformed lines fit very well...

I bought the Holley fuel line from Mancini (http://www.manciniracing.com/ho41chfuli.html).  I did have to slightly bend it to get it to fit right, nothing major but it originally did not line up perfectly.

[theseoldcars]

I'll add my welcome to the site too.  Are you in the UK?

Hello Ghoste; thanks. Yes, I'm in the UK. I used to have a '68 Firebird (and some Corvettes, many moons ago) but I sold it and nothing else I bought really filled the void. In March this turned up just down the road from my parent's house and, having looked at it, I couldn't walk away.

Done a fair bit to it but down to the details now, like refitting the door and panel rubber bumpers, changing the belts and stopping a few minor leaks. Then I can start using it properly.

[Ghoste]

It looks great!

[funknut]

Indeed.  Beautiful '68!

[theseoldcars]

Thanks funknut, Ghoste. Hope you're well!