304 V8 Carb Or Fuel Injection - I Know Beat To Death Variables

1972 - CJ5 - 304v8 Pretty much all stock, full restore 14 months ago.

Current setup: Edelbrock SP2P Intake was on it when I got the jeep - AVS2-1906 4bbl carb 650 cfm, HEI, timed @ 8 BTDC
Problem: Absolutely HORRIBLE off road, loads up, floods out blah blah. I know the carb is way too big. Does just fine on asphalt, power wise etc, but put it on a forest service road lugging and pulling hills, I should just get out an walk due to it loading up etc.

I am thinking 2 of probably 100 ways to fix this.

1. Go with K247J Howell Injection as the jeep is ready to accept. Problem is determining if the SP2P manifold will work with their 4bbl adapter. Howell is researching but finding a spec sheet for dimensions of mounting holes etc on an SP2P went out with the last T-Rex. Trying to find this before I take off existing carb.

2. Get a used OEM 304 2bbl intake manifold ( see them for $100-$250) on ebay/facebook. Install a Motorcraft 2100/2150 carb and cross fingers this works. I know it is still carbureted.

Not at all keen on keeping the SP2P as I understand it is a low flowing runner fuel efficiency manifold that pretty much everyone hates, but I don't want to put in $500 for a new 4bbl intake and $500 for a 500/550cfm carb that I am thinking keeps me in the same current position.

I know lots of talk on either Howell or Holley etc etc systems, but from searching forums people seem to really think the Howell system is at the top.

SOOOO, I am thinking it may be the best solution to go with the OEM 2bbl intake with the Howell injection. I would appreciate any input or ideas. I will probably do something by first of year. Jeep is not a daily driver per say, but do need it available as a 2nd vehicle.

 

I can’t believe I’m saying this, but I vote 2100 unless this thing is really where you want to sink the amount of money, troubleshooting, and time into. They’re great carbs when set up properly, and it’s a basic engine that would do well with it.

 

Having a similar system on my 4.3 as what Howell uses. I would go with a user tunable and self learning system like the holley sniper.
The issue with the Stock TBI is the computers are pushing 30 years of age and were made to be in an enclosed area of the car.

 

An equal length runner dual port manifold would be better however, you don't want to spend the money.

That being said, the intake looks like it will take a spreadbore carb. If so, I would recommend either a Quadrajet or the now discontinued Holley Economaster. Both perform very well offroad and the tiny primaries will give both crisp throttle response as well as better fuel economy.

Otherwise, a smaller square bore may be the ticket. You have a Holley 390 or 470, or a smaller Carter (Edelbrock). Carter made a 400CFM AFB, but it is obsolete as well.

Third choice is the one above. A solid MC2100 with the 1.08 venturi is a tried and true upgrade.

 

I took the 2100 from my 304 and put it on my 360. Not a powerhouse but it runs great. No electronics to go out out the woods.

 

With the MC2100 it’s all about the jets and fuel pressure

 

This. Most basic carb in the world, and they work pretty good off road. The AFB/AVS/Edelbrock series carbs are great street carbs, but as you've found, don't work well off road.

 

I would say until you are ready to buy all the parts you want for a fuel injection setup, find a 2100/2150 and bolt it to your current intake. The SP2P is a low volume intake but in does have descent runner velocity.

 

You know, another option that is never talked about is the bigger 2G series that GM ran on it's V8's. Anyone who has used it's smaller cousin on the V6 will attest to it's reliability and economy. Might be another cheap option.

 

Big fan of the 2G. Running one on a SBC 350 with SP2P manifold and RV cam. Great low speed drivability but runs out of breath at high rpms. Duh. The larger version (2GC I believe) would fix it.

 

Thanks you guys for the feedback. It does make economic sense to try the 2100 with my existing SP2P. Will just need to source the spreadbore adapter and 2100.

 

the 2100 in my dead jeep worked mint never gave any troubles in the years it was alive...rip max

 

looks like a 1929.
Huh,
cant get the chart to load.

 

At least it did until you shot it thru the carb.

 

FI wins every argument especially if you want to actually drive it.

 

There it is

 

I had to end the suffering

 

The carb you can get at any parts store. Mid 60’s f100 with 302.

 

x2, plus if you find a used one, parts to completely rebuild the 2100 are very reasonable too. And rebuilding them is a simple.

 

I rebuilt my 2100 this summer. It was marked as a 2105
Mike was great help on the phone to make sure I had the proper kit for my carb.

https://www.carburetor-parts.com/2100-carburetor-parts