304 advice?

Just bought a '73 304 to put in '73 CJ5 that I bought with no engine. (was 304, PO threw a rod)
Engine has just under 60,000 miles and is a good runner. Going to be 99% trail rig.
Looking for opinions on carbs, headers, and clutches.

 

As far as carbs go, I recommend motocraft 2 barrel. I've run several differnt 4 barrel setups on mine, and they all seem to have thier pluses and minuses. If you do have to have 4 barrel, the edlebrock series are nice for tuning.

If you have an idea of what you motor will be running for max RPM, you can figure out what size carb you need.

304cu in * 5000 rpms, * 1/2 of those RPMs its sucking air, / 1728 to convert to cu ft = 440 CFM assuming 100% vacuum efficiency. In reality its prob needs less than 400, taking into account vaccuum.

 

I know lot's of people will recommend the MC2100...But, I'm going to go ahead and say Quadrajet. I just feel that with the small primaries you'll save some gas, and the float bowl location is perfect. It really is great for off-roading. You would need a new intake so I'd say go with the edlebrock performer. As for headers, Black jacks and hedmans perform well and run reasonable but if you HAVE to have the best...It's hooker headers all the way. For clutches the stock version is plenty, I wouldn't go with a diaphram style clutch if you paid me..The Borg and Beck style is really very heavy duty. I wouldn't get into the centerforce or anything unless you plan on street racing, mudding, or something stupid.

If it was me I'd keep it reasonable, the hedman headers work just as well on a 304 with no cam or w/e. Although I'd still get a Q-jet just because I favor 4bbl carbs. I picked up an edelbrock performer locally for $75 and I know for a fact you can find Q-jets on friggin everything in the junkyard so it's really not that pricey. Actually you can probably get a Q-jet, rebuild kit and the intake for about the same price as most people want for the MC2100...Go figure.

 

I'd avoid headers on a Jeep. Noisy, leaky, hot, expensive, fragile. Strictly race car tech.

The Jeep cast iron exhaust manifolds flow well, for iron manifolds.

The stock carb (Motorcraft 2100) is fine, and one of the best off-road carbs, as is the Quadrajet. However, there's no source for either of these carbs new, so if you want a new carb, the 470 CFM Holley Truck Avenger is probably your best choice.

IMO, the 304 is a lot of engine for a Jeep. I'd go stock with aftermarket EFI; maybe a mild cam too.

 

I agree with tim. THe 304 makes plenty of power for most applications. Jsut ask my sheared driveshafts and blow spider gears, lol.

THe stock 2bbl is a very good carb. I've also heard people who were very happy with the Holley truck avenger series. Probably the 470cfm for a 304 would be about right.

Stock clutch can take alot of abuse, no real need to upgrade.

 

I'd only stay away from the headers if you're going to be a rock crawl rig.
The AA headers on my Jeep have been on there for over 25 years, and I've had none of the problems Tim describes.
The stock iron manifolds can and do crack/break over time with usage.
I suppose if money were the issue, use the stock manifolds.
Most engines will respond nicely to headers; I know the V6 does.

 

I've never had much luck with headers either. But, that was old Hookers 25 yrs ago. I was hoping new ones these days were better.
I have had great luck with Edelbrock carbs in the past and was leaning towards them, but, I may have to look at these others.
I'm too old to learn EFI! (last of the dinosaurs!)
As silly as it might seem to some, I'm even sticking with the old points and condensor setup. I understand them and spares can be easily carried and replaced on the trail.

*ReLoaded,

"For clutches the stock version is plenty"

*DrDanteIII

"Stock clutch can take alot of abuse, no real need to upgrade."


That's good to know, I was wondering if I should be looking at an aftermarket one. Stock it is!

*Monteypython

"If you do have to have 4 barrel, the edlebrock series are nice for tuning."

That's what I liked about them too. Easy to set and STAYED set!

 

One option for the clutch is to use the 11" clutch from a Jeep pickup. I know of people that have done this, but I have not. The 11" kit is about $30 more than the 10.4" kit called for as a replacement, on rockauto.com.

 

Truck avenger carb all the way, Edelbrocks suck offroad, I don't care what you do to them. Edelbrock or Doug thorley shorty headers work great, hedman and hookers have thin flanges that warp and leak.

 

I would have to say that the MC2100 works very well with my 304. It provides more than enough power for the mild wheeling that I do. As for headers, i've ran them as long as I've had the rig with no issues. The pair that came on the rig (unknown how old) worked well until I crushed one of the pipes just before the collector on rock. This rock must have been imported from Texas, it was that big R) Anywho, just picked up a new set from headman for $126 brand new. Haven't tried them out yet, but they went on just fine. They use a gasketless kajigger at the header collector, we'll see how it works.

 

Where'd you score the Hedmans for $126?

 

headers:
careful on your header choice-i have fenderwell headers and when i put larger tires on, the hit the headers on full turn, therefore i'm switching to in-frame headers. i've heard a lot of great things on shortys, i just don't have the wallet for them at this time.
never had a problem with my headers, bounced them off rocks and such, just little dings, no major problems other than tire clearance issues.

carb:
i have a holley 2 barrel, don't know which one (but it's all mechanical). works great for me. my friend put a edelbrock off-road on his chevy 305, LOVES IT. it works at better angles than mine does, especially severly off camber and steep inclines (and the combo). if i replace mine, i will be switching to that.

good luck

 

4WD had a End of the year sale, got them for 20% off and had em shipped to the store in portland to get free shipping. Only complaintwas the 2 1/2 weeks to get them shipped in, so I overshot my window of time off from work to install them.

 

Two words stocker & locker.

I hate my headers. I trade you for you manifolds. I like a clean line under belly and my headers hang down to 2 to 3in below the tub.
MC 2100 can take some high angle trails. (the ones in these parts anyway)
As for clutch I never had any problems with stock. No problems

Safe you upgrade $ for locker(s)

 

I've had a pretty good experience with the Centerforce Dual-Friction Clutch. Of course, it depends on what you want to do with your jeep. That clutch is GREAT for sand drags and racing in general.

 

I have a Holly 500cfm carb with Hedman Headers on my 304. I really like that setup, plenty of power. The Holly carb bowl is on the front so it works great on steep inclines. I also have the Centerforce Dual-Friction and it hooks up awesome. However most of my off-road time is in the dunes.