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Old 04-30-2010, 06:43 PM
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802Hoop 802Hoop is offline
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I NEED AN OFF ROAD CARB! What kind is on an '80 J10?

So I own two J10s, an '81 Sportside and an '80 townside parts truck.

Anyway, I'm doing a motor swap (parts truck 360 into the '81 sportside). The '81 has a 258 with a Holley two barrel on top that does well off road, but it's a pain to tune. Here is my question:

If the 360 out of the '80 parts truck has a factory two barrel, what carb does it have?, assuming it's stock. I live in Tampa (stationed here) and my trucks are in Vermont (at my old folks house), so I can't just walk outside and look it up. I am trying to decide if I should install the Holley on the existing manifold, stick with what is on the 360 now, or should I find a descent 4 brl and manifold?

This truck spends the majority of it's time off road, and I trying to find the best setup for it's use. My priority list goes as follows:

1-Reliability (because I just want to drive it when I get the chance)
2-Side angle ability
3-Power
4-MPG

If the stock 2 brl is a Motorcraft MC2100, I may just stick with that for it's off road performance, but now that I'm thinking about it, I may just need to rebuild the Holley... I dunno. What are you thoughts/inputs?
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Old 04-30-2010, 06:47 PM
joe joe is offline
 
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Stock should be MC2150.
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  #3  
Old 04-30-2010, 07:21 PM
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You don't wanna use a six banger carb on the V8. It would take some major rejetting to make it right, and it'll still be very low CFM for the job. I know some people have done it, and made it work, but I would suggest that you rebuild the carb on the V8.

By the way. I'm a native Vermonter now living in Orlando. Where you from in Vermont? For all I know, you could be a relative, or at least know my family.
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Old 04-30-2010, 07:24 PM
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Quote:
Originally Posted by []V[]AXX
You don't wanna use a six banger carb on the V8. It would take some major rejetting to make it right, and it'll still be very low CFM for the job. I know some people have done it, and made it work, but I would suggest that you rebuild the carb on the V8.

By the way. I'm a native Vermonter now living in Orlando. Where you from in Vermont? For all I know, you could be a relative, or at least know my family.

White River Jnct area. You?
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  #5  
Old 04-30-2010, 07:45 PM
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My vote is for the motorcraft 2150. They are very difficult to flood offroad and also very easy to tune and work on. As far as carbs go, I'd say they are the next best thing to fuel injection
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  #6  
Old 04-30-2010, 07:46 PM
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Vergennes/Bristol. I don't know many in White River, but I'm sure my grandparents do. The Bushey family is pretty big.

Pretty rare to find anything up there that hasn't rotted away. Good to know there are some people up there that kept em goin. Look forward to seeing you on here.
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  #7  
Old 04-30-2010, 09:36 PM
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Quote:
Originally Posted by []V[]AXX
Vergennes/Bristol. I don't know many in White River, but I'm sure my grandparents do. The Bushey family is pretty big.

Pretty rare to find anything up there that hasn't rotted away. Good to know there are some people up there that kept em goin. Look forward to seeing you on here.

Doesn't ring a bell. But I played soccer every now and then in Vergennes about 8-10 years ago. Flattest part of the state, lol!

My truck has it's share of rot, but it's soul is fully intact!
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Old 04-30-2010, 09:46 PM
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Power-wise, will I regret going with the 2 brl? It definitely seems like the way to go for the off road driving. What kind of CFM am I looking at with the MC2150? I have a bit of money left in the budget to spring for a new carb and intake, but I'm leaning towards putting that money into the ignition system instead. Thoughts?
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  #9  
Old 04-30-2010, 11:32 PM
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getlost4x4 getlost4x4 is offline
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i like my 2150. it didn't flood out on me the only time i tried it off road. its really easy to tune and work on.

my 360 has plenty of power. i also have a RV cam in it. working great so far!
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  #10  
Old 05-01-2010, 08:31 AM
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I was just looking into 2150 sizing. Another off road forum says that there is a number stamped somewhere on the side of the carb body that shows the venturi size for that particular carb.


Number = CFM
.98 = 190
1.01 = 240
1.02 = 245
1.08 = 287
1.14 = 300
1.21 = 351
1.23 = 356
1.33 = 424

So, the biggest it could be is 424 CFM. That seems a little small for a 360 CID engine, but since everyone here swears by them, they must do the job. Anything else is major surgery. Since the trucks are in Vermont, they'll need a working choke.

I'd like to put a propane conversion on my truck. I'm in Florida, though. I'm not sure how they'd do in extreme cold weather operation. For now, get a bucket of chem dip, and a kit.

I think you're on the right track with the ignition system idea. I'm constantly seeing complaints on that score. Most guys on here seem to go Ford TFI, or GM HEI. I would skip that, use a stock distributor, and go with a digital ignition control. I like the Mallory Hyfire 6 over the MSD ignitions for the price, and power. The Hyfire 6AL has a rev limiter, so that's the one I use. It's about $180, though. It is not difficult to connect, either. Using the stock distributor will ensure that when it goes, you can get a replacement that fits, with a warranty, and no modification required.
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  #11  
Old 05-01-2010, 01:10 PM
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JERSEY JOE JERSEY JOE is offline
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off road carb

The 470 Holley Truck Avenger is a good setup.

I have heard that a backward mounted Rochester Quadrajet is the best carb setup going....
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  #12  
Old 05-01-2010, 09:59 PM
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Yeah, definitely read a bit on the success with quadrajets. I appreciate the input guys.
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  #13  
Old 05-03-2010, 09:20 AM
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it may also depend on your elevation. i live at nearly 5000 feet and i go up to 11000 ft when i'm 4 wheeling and camping. a small carb works best around here where the air is thin.

but i will probably be going to TBI this summer. i really hate carbs. this one starts fine in 30 degree weather, but anything lower and it gets harder to start.
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  #14  
Old 05-04-2010, 10:04 AM
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cable97526 cable97526 is offline
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Quote:
Originally Posted by []V[]AXX
I was just looking into 2150 sizing. Another off road forum says that there is a number stamped somewhere on the side of the carb body that shows the venturi size for that particular carb.


Number = CFM
.98 = 190
1.01 = 240
1.02 = 245
1.08 = 287
1.14 = 300
1.21 = 351
1.23 = 356
1.33 = 424

So, the biggest it could be is 424 CFM. That seems a little small for a 360 CID engine, but since everyone here swears by them, they must do the job. Anything else is major surgery. Since the trucks are in Vermont, they'll need a working choke.

I'd like to put a propane conversion on my truck. I'm in Florida, though. I'm not sure how they'd do in extreme cold weather operation. For now, get a bucket of chem dip, and a kit.

I think you're on the right track with the ignition system idea. I'm constantly seeing complaints on that score. Most guys on here seem to go Ford TFI, or GM HEI. I would skip that, use a stock distributor, and go with a digital ignition control. I like the Mallory Hyfire 6 over the MSD ignitions for the price, and power. The Hyfire 6AL has a rev limiter, so that's the one I use. It's about $180, though. It is not difficult to connect, either. Using the stock distributor will ensure that when it goes, you can get a replacement that fits, with a warranty, and no modification required.

There are a lot of reasons that we go with TFI/HEI systems. Some guys do it for the output, other like me HAD TO do it because the small distributor rotor and cap tend to melt down when connected to an MSD SCI box and Blaster II coil. The ford TFI cap and rotor is almost a must when your using a discharge box because of spark crossover inside the cap. FYI Hyfire and MSD are the same company along with Streetfire and if it were me doing it all over again I would use a Streetfire CD box, it has soft touch rev control, great output and the PRICE! $128 at your local Oriley's.
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1974 J10 Levi's edition 401/th400/np205 60/14 soon to be 8.1/4L85E/205!
1968 J20 SBC350/sm465/np205 60/14
1972 Cherokee Chief (stock)
2003 TJ Rubicon Tomb Raider turbo/40's/D44F/9inchR
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Old 05-04-2010, 11:01 AM
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Quote:
Originally Posted by cable97526
There are a lot of reasons that we go with TFI/HEI systems. Some guys do it for the output, other like me HAD TO do it because the small distributor rotor and cap tend to melt down when connected to an MSD SCI box and Blaster II coil. The ford TFI cap and rotor is almost a must when your using a discharge box because of spark crossover inside the cap. FYI Hyfire and MSD are the same company along with Streetfire and if it were me doing it all over again I would use a Streetfire CD box, it has soft touch rev control, great output and the PRICE! $128 at your local Oriley's.

Well, as far as melting caps, I've never had that problem. That isn't to say that you can't benefit from a better cap and rotor, I've just never had any problems as long as I bought decent parts. The Autozone caps are super thin, so I buy from Napa or a local parts house that carries a better quality cap. I've also never had problems with spark crossover on a good quality cap. Mine works fine. If you melted a cap, something was wrong.

Next, MSD and Mallory, (who makes the Hyfire ignitions) are not the same company. Prestolite performance owns Mallory, Accel, and a bunch of other names. MSD is it's own company. MSD is the one that builds the Streetfire ignitions. Try checking that out next time before assuming or believing the guy at O'reilly. The Streetfire has received good reviews, and I'll admit, I've never used it. I can tell you that the Hyfire ignitions are more efficient and give a hotter spark than the Street Fire boxes, weather the additional 40mj of energy are worth the price, I don't know. When I was looking for an ignition box, I got a combo price on the Hyfire and the e-core coil to go with it, so it was a good deal. I would like to see a head to head between the two, just to see how it works out, because the Streetfire is cheaper.
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Old 05-04-2010, 12:18 PM
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cable97526 cable97526 is offline
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Quote:
Originally Posted by []V[]AXX
Well, as far as melting caps, I've never had that problem. That isn't to say that you can't benefit from a better cap and rotor, I've just never had any problems as long as I bought decent parts. The Autozone caps are super thin, so I buy from Napa or a local parts house that carries a better quality cap. I've also never had problems with spark crossover on a good quality cap. Mine works fine. If you melted a cap, something was wrong.

Next, MSD and Mallory, (who makes the Hyfire ignitions) are not the same company. Prestolite performance owns Mallory, Accel, and a bunch of other names. MSD is it's own company. MSD is the one that builds the Streetfire ignitions. Try checking that out next time before assuming or believing the guy at O'reilly. The Streetfire has received good reviews, and I'll admit, I've never used it. I can tell you that the Hyfire ignitions are more efficient and give a hotter spark than the Street Fire boxes, weather the additional 40mj of energy are worth the price, I don't know. When I was looking for an ignition box, I got a combo price on the Hyfire and the e-core coil to go with it, so it was a good deal. I would like to see a head to head between the two, just to see how it works out, because the Streetfire is cheaper.

Sorry about the miss information on that post that was my fault and not the IDIOT's that work at Oriley's. Now on to the second thing, if you've never "melted" as I call it or more appropriately named burnt the lugs on a small cap then you've never run a motor at high rpms for any extended time. The caps I was using on mine and a few other rigs were BWD's from NAPA not cheap useless garbage from autozone/Orileys/checkers or any other chain store. It is a common occurrence for distributor cap lugs to become electrically burnt under high load situations in small cap conditions. If you would like to familiarize yourself more with this before stating something on my end may be wrong then read this directly from MSD site:

Distributor Cap and Rotor: It is recommended to install a new distributor cap and rotor when installing the MSD Ignition Control. The cap should be clean inside and out especially the terminals and rotor tip. On vehicles with smaller caps, it is possible for the air inside the cap to become electrically charged causing crossfire which can result in misfire. This can be prevented by drilling a couple vent holes in the cap. The holes should be placed between the terminals, at rotor height and face away from the intake. If your environment demands it, place a small piece of screen over the hole to act as a filter.

Next here is a turnout from Off-Road
http://jeep.off-road.com/jeep/articl....jsp?id=543504

There are a lot of reasons more than I have shown here why you would go to a larger cap, if you can't see why then I will stop trying to give my humble opinion.
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Old 05-04-2010, 01:53 PM
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Nothing wrong with sharing ideas here... I'm not too worried about spending a few extra bucks on a set-up that's a little more heavy duty. I need the reliability, but with all the moisture that I see off-road, I can't start drilling holes in my distributor cap either. It would probably work okay for street use, but I would still be a bit skeptical.
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Old 05-04-2010, 01:56 PM
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Quote:
Originally Posted by 802Hoop
Nothing wrong with sharing ideas here... I'm not too worried about spending a few extra bucks on a set-up that's a little more heavy duty. I need the reliability, but with all the moisture that I see off-road, I can't start drilling holes in my distributor cap either. It would probably work okay for street use, but I would still be a bit skeptical.

That is the exact reason why you would use the later model ford TFI cap. Read through the link I posted at the top and you will see.
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1974 J10 Levi's edition 401/th400/np205 60/14 soon to be 8.1/4L85E/205!
1968 J20 SBC350/sm465/np205 60/14
1972 Cherokee Chief (stock)
2003 TJ Rubicon Tomb Raider turbo/40's/D44F/9inchR
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Old 05-04-2010, 06:57 PM
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Were we talking Jeeps or race cars, boss? You may want to reread my post. It's not often we run these things at high rpm for long periods, except maybe on the interstate. I did not state that it doesn't happen, I stated that I'd never had a problem with it. That being said, if you bought a good quality small cap, you may have noticed that they have a vent built in. That tower on better caps is a vent to help prevent what you're describing. If the cap doesn't allow a tower, many already have the vent holes drilled, or vents on the bottom. The only time I've had problems with static misfire is on a boat with an inboard mounted engine. A Mercruiser drive with a Buick V6. Small cap HEI, with a sealed cap for marine use, and then only after pulling a skiier around the lake for a few hours. You can buy vented or sealed caps, depending on application.

I wasn't saying don't do the TFI upgrade, but I don't think that the TFI system by itself goes far enough. I think the aftermarket box is the way to go. The digital ignitions are more efficient, and give a hotter spark. If you're cooking caps, there may be other issues. Poor grounding comes to mind, along with bad plug wire routing or loose terminals.
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Old 05-04-2010, 09:58 PM
Blake Blake is offline
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I'm running a 670 holly truck avenger on my fresh amc 360 in my J10 truggy. So far it's a GREAT carb. I've had it on some very steep angles and have yet to see it stumble. I'm able to idle over some hairy stuff with no problems.

Had it up to just over 10K feet with no problems either.

Bought it used on craigs for like $150, bolted it on and it started right up on first try.
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