Best carb for 383

[pkhanc]

Hi everybody, first time to post so bear with me.  I have a '74 Challenger that I purchased a few years ago.  I enjoy driving it as a weekend cruiser and have had no real issues until now.  It has a 383 with a Thermoquad and 727 tranny.  The TQ has started leaking gas like a crazy so I am sure that it needs a rebuild.  However, in checking the numbers on the carb, it shows it was originally for a 1978 440.  I'm not real crazy about staying with the TQ, and wanted to see what advice the forum has on replacement carburetor.  The 383 was built when I got it, so I don't have personal knowledge of what was put in it.  Supposedly, it was bored .30 over, etc., etc..  I don't run it hard, but do like to nail it occasionally.  It has always run very strong, plenty of everything that I want as a weekend cruiser.  But, if I'm going to lay out for a new carb, I don't want to spend a lot of money experimenting.  Any suggetions for a good reliable replacement?

[Chryco Psycho]

Welocme
 In My opinion the 82751 Holley 750 HP street series

[dodge freak 2]

Yes the HP series are great but I believe thats a Double Pumper carb. We don't even know the gear ratio or type of trans, auto or manual and if its an auto does it have a high stall converter or 4.1 gears. Plus it sounds like its more of a rider than a hot rod.

I think the 82750 with vacuum secondary s might be a better pick from him and that car, even thou wide open in top gear on the freeway it might not be as fast. From a dead stop with a like 3.21 gear  a DP carb will give him that dreaded bog for the first 2 seconds. Then he need 3.91-4.1 gears and his gas mileage will go down....but it be blast taking off.

1974, yeah those came with 3.21 gears or so. You even have headers on it, if not the DP carbs not going to run as  good wide open.

Vacuum secondary s carbs will run good in all cars but sometimes a DP would be better but not always.

[sleepychallenger]

says its an auto. i have the factory 625 cfm carter on mine and it does great.

[dodge freak 2]

The TQ's are all vacuum secondary's carbs. Not just like the Holley but works like the same.

Its alot of $$$, so since it seems like he not a speed freak, a vacuum secondary--to him--might be more fun to drive since he could keep the rpms low and still punch it.

We really need to know the trans and gear ratio and what you want. It sounds to me you want a easy carb to drive, even if not as fast as it could be.

Oh yeah, 727...guess its past my bed time ha ha. It most likely does not have a high stall converter or 4.1 gears. Carters can be good to be I love Holleys but gee.

You know what. I THINK Edelbrock give a 1 year deal if you buy a new carb from them, those are Carters with eddys name on it, from a place like Summit Racing or Jegs and you are unhappy with it, you get your money back !

But a Holley, even a vacuum secondary most likely will make more power, once tuned right.

[pkhanc]

Hey guys, thanks for the response so far.  As for me, I'm just a weekend cruiser.  Years ago, I was, (or thought I was), something of a speedfreak.  These days I just like it to look good, run good, and be dependable.  My car orginally was a 318 car, but the guy I bought it from 7 years ago was a former Chrysler employee.  He built it the way he wanted it, then sold it to me when he left to be a missionary.  He couldn't remember everything that he did to it, as it was a project for about 6 years, but it was bored .30 over, has a mild cam and a stock intake that was deburred and "opened up" as he called it.  The TQ was something he picked up at a swap meet.  The 727 was rebuilt last summer and retains the shift kit that was in it when purchased.  I have no idea about the rear other than it is a 8 3/4 and is not a posi unit.  I have put 30,000 miles on this car since I purchased it and can say he did a great job in building it.  It has been reliable and fun to drive.  The TQ has been pretty bullet proof although it sucks on take-off.  But, above 3500 rpm, you just shut up and hang on!  So, after listening to the others I hang with, (who know nothing about Mopars), I am seeking the advice of true Mopar addicts.  I want a carb that I can put on and run and not have to worry about major tuning.  Thanks!!!

[cudabob496]

I think you would be happier and quicker on the street with a 650 carb. My built 440 made close to 500 hp, and I ran a 750 double pumper on it.

http://www.carcraft.com/techarticles/selecting_right_carb/index.html

[dodge freak 2]

"major" tuning is putting the right jets in it. Its really not that hard. It be jetted close but it might need both jets in front 1-3 sizes bigger. You know once you drive it for a few days, if its not smooth at all speeds or seems good once its been running for over a 1/2 hour, then its a bit lean and on a holley you just remove 4 screws and go up from the jets that are in it.

650-750, with a vacuum sendory carb. either one would work, with the 650 getting a bit better gas mileage, which is good now of days.

Barry Grant carbs have more to pick from than the holley it those sizes. Or its Edelbrock's Carter carbs-which some here hate.

Sounds like you lived with a out of tuned carb too long, you really need to get them set up right to start with. With your intake a 750 might not fit the primary holes in the intake too good too. So maybe the 650 would be best, but stay away from the DP oh and most 750 and 650 use the same base plates, so they both will be too big without a spacer the fit your intake.

Holley does make a TQ replacement with big secondarys and small primary's but they come both in DP and vacuum, again I would pict a vacuum for that car. Wow they are not cheap...

http://store.summitracing.com/partdetail.asp?autofilter=1&part=HLY%2D0%2D80555C&N=700+4294925239+4294839063+4294919007+400178+4294908158+115&autoview=sku

Those fuel bowls are the poorer style too, well heres the Eddy carb which would fit good too--I think, not sure if the intake secondarys holes are so big the carb would leak, don't think so but you should look  if you put it on...

http://store.summitracing.com/partdetail.asp?autofilter=1&part=EDL%2D1806&N=700+4294925239+4294839063+4294919007+400065+115&autoview=sku

[pkhanc]

Hi again.  Thanks for the input so far.  It makes my research much better with the feedback.  In another thread on this forum, I read about the Holley refurbs.  I did a little research on eBay, found the Holley site and found this carb that is selling.  Here are the spec's as lifted from the ad.

Item:  Part Number FR-80508S  750 CFM 4-bbl Vacuum Secondary Carburetor with Electric Choke

1.  Vacuum secondaries for use on a wide variety of vehicles.  Compensates for vehicle weight, gearing, and   
    transmission
2.  Electric Choke
3.  Ball burnished silver zinc finish
4.  Power Valve Blowout Protection to keep backfires from damaging power valves
5.  Duel Feed Fuel Inlet for ease of plumbing
6.  Vacuum ports: 2 Full Manifold, 1 Timed Vacuum for ease of installation
7.  Model 4160 W/Center Hung Floats

In reading the tech article on the carb, it can be used for Chrylser products.  They list the items needed for use on a Chrysler, throttle position pin, etc., nothing major.  Dodge Freak 2 mentioned the adapter, that's not a problem.  How about the automatic transmission kickdown.  Will there have to be any modifications on it?  I remember about 3 years ago, this got out of whack, and it took me forever to get it set right.

[dodge freak 2]

Its not too bad but then again once I switched to a manual valve body and got rid of my kickdown linkage. I was 1 happy guy.

How I used to set it was at wide open throttle and adjust it so the kickdown is also as far back as it can go. I used to use a bolt and nut in the long slot area, instead of trying to bend the rod just right.

That carb,  http://cgi.ebay.com/ebaymotors/750CFM-Holley-Factory-Refurbished-0-80508S-Carburetor_W0QQcmdZViewItemQQcategoryZ33550QQihZ023QQitemZ360009672539



Is cool but is smog ready, no big deal but I bet it be too lean and need bigger jets. Also theres no metering block for the secondarys. You need the block and 4 longer screws and some jets-around 80-to adjust it. I would get it before you get the fuel line or get an adjustable fuel line or you would need a different line after the sec. block is in.

Holley has raised the min. bids for the new year it seems like. That was like at $175 but it may be higher now, 10-20%.

I like theses too..http://cgi.ebay.com/ebaymotors/570CFM-Holley-Factory-Refurbished-0-80570-Carburetor_W0QQcmdZViewItemQQcategoryZ33550QQihZ023QQitemZ360009706095

It comes in 670 and 770 models too--they be on in a few days, holley updates it site 1-2 times week. Those mins did get raised, were like $189 and last night a $202 bid was not high enough. Those carbs have the secondary metering block already. Thats what I would get and yeah the 670 might be better for it than a 770.

Now your intake front holes will be too small, you would need to raise the carb a bit or remove the intake and hog out those holes--if nobody has even done that yet. It be hard too with being cast iron. A shop could do it for you or buy a diff. intake--I know more $$$   

[Oldschool]

My vote is the Holley 750 HP.  I am a huge fan of the double pumpers over the vacuum though.  Way quicker off the line imho......       

[dodge freak 2]

My vote is the Holley 750 HP.  I am a huge fan of the double pumpers over the vacuum though.  Way quicker off the line imho......       

When you have enough gear for it. That car might even have 2.73 gears, he does not know--even doesn't know how to check--so if I was him I would get the easy to tune carb.

Yes DP are the best carbs off the line and at all speeds, when the rest of the car is set up right for it.

[dodge freak 2]

I have a DP 750 and everything for it but a high stall converter but do have 3.91 gears, with a 2.74 1st gear auto 904 trans. Car takes off great but if I go around a conner from a stop 1st gear by the time it straightens out is like too much and 2nd gear is not enough until I wait until its going 40 mph. I got beat by a newer corvette last week doing do that but a few miles before that on a straight shot  from a dead stop, I let it get the jump on me and by the time I was @ 6000 rpms in 1st I was even and by 6000 rpms in 2nd I was 2 car lengths ahead and was pulling  away good--I am sure it wasn't a Z06, just reg vette and I bet it was an auto.

But my DP hurt me getting off the freeway and then a vacuum secondary would have been better or a 3000-4000 stall converter but my gas mileage is only at 10 mpg now.

If I had 3.08 gears my DP would have stunk...

[dodge freak 2]

You know looking at some 360 stock intakes on E-bay those front primary holes don't look all too small, maybe a 650-750 holley would fit fine. IDK, I do have a 1969 AVS stock intake and when I put my 750 holley on it the front holes of the intake were a tiny bit smaller, so I just thought the TQ intakes would be smaller yet but maybe not.

[pkhanc]

Thanks for all the input.  I am going to go ahead and upgrade the intake as well when I buy the carb.  Tentatively, I'm going to go with the Edlebrock Performer and the Holley 750.  I'll determine the rear end ratio and let that be my guide for final carb selection.  The rear end needs to be gone thru, so this will be as good a time as any to find out exactly what is in there!  This forum is the best place for people like me to get good advice from people that actually have a Mopar!!!  Thanks guys!