Reference: 1970 F100 w/ 360, 2100 manual choke carburetor.

Carburetor is tired and needs a rebuild, hate the access to the drivers side fuel screw, passenger side is fine.

Getting back into old trucks after tinkering w/ dirt bikes for over 30+ years. Access to dirt bike carburetor fuel screws sometimes are just plain horrible.

Typically an aftermarket Company will come with a nifty access part, or tool, does anyone make one for the 2100 driver's side ???

Come to a fork in the road, I know the 2300 is easier to tune, due to access, coin toss on performance I would imagine, I would be going for the 2300 350 cfm.

Opinions appreciated !!!

Thx !!! Michael

 

A rebuild kit for a 2100/2150 is like $25.

A newish 2300 is $100 or more. A new-new one is $300+ IIRC.

Pick your poison. ... Me? I'd rebuild the 2100/2150 and see how it does... it's not like ya have to tune it on a monthly basis. Maybe twice a year between summer and winter given that yer in Roseville... basically the same conditions here in Concord/ Walnut Creek/Pleasant Hill.

 

So the 2100 / 2150 you can only adjust the idle mix twice a year.
Now what if it runs too rich driving? Remember it has nothing to do with idle mix as you are no longer on idle.
So where can you get jets for them?
How bout power valves in different HG's?
Where can you get the carb gaskets, not the base gasket. Oh heck base gasket with out ordering it.

The Holley 2300 both the 350 & 500 CFM are half a v4 Holley. Any speed shop if you have one close or get parts on line.
Because it is half a v4 all the tune up parts are the same, gaskets, jets, power valves you name it.

BTW I have a 2300 500 CFM on an AMC 304 that replaced the POS Motocraft 2100 I could not get to run right even after a rebuild.
It was the best thing I did to the car / motor. I know I changed the power valve, might of gone 2 leaner on the jets also but been so long I don't remember and I don't remember where my notes are on the car at this time.
My son runs a 2300 500 CFM (little too big but was on the shelf) on a YJ Jeep with 258 L6.
I also have a Holley pit box when I go racing, it has jets, power valves, gaskets, springs for v4 carbs, vent whistles, etc.
If you cant tell I am for the Holley 2300 but on the 360 would go with a 500 CFM.
Dave ----

 

1970 360 used an automatic (not manual) choke. If you actually have a manual choke, then the OEM choke has probably been swapped out.

The decision to rebuild vs. replace should depend on whether the carb is worth rebuilding. Some of these get so worn out that a rebuild kit just isn't enough to get them running right again.

You can adjust them more than twice a year. The awkward part to adjusting them, for me, is that I have to lay on top of a running engine while I make the adjustments. That's an unhappy place for me, even if I'm using a piece of plywood to support myself.

 

Thipdar,

Hate to burst your bubble, it is a manual choke and period correct.

I can't see the previous owner going through the aggravation of boring a hole in the dash and putting in a manual choke system and eliminating the auto choke.
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Fuzzface,

Thanks for the feedback on MC 2100 vs. H 2300, It feels pretty worn out, idle mixture screws feel way sloppy.

BTW, why the 500 over the 350, I would think that the 350 would have more initial torque than the 500 and

with this low compression motor, I would think that torque is the last thing you would want to give up.

Appreciate the feedback Guys !!!

Michael

 

I am a Holley fan usually but I vote to rebuild the 2100 1st. As long as it's rebuildable as Thipdar said. The 2100's annular discharge booster venturis are closer to fuel injection than the Holley 2300's standard venturis. As far as air/fuel atomization goes.
Look down the throat of the carb and make sure the venturis have not melted from any carb back fires in the past. Grab on to the throttle and move it around to make sure the throttle shaft isn't too loose in the carb's base plate. This would act as a vacuum leak. And check that base plate for any cracks from someone over tightening the carb to intake. This kind of crack usually crawls right up the carb. And is also a vacuum leak.
If you have a manual choke than either the original carb has been adapted or an older carb was installed. 1970 was the 1st year for electric choke in a Bumpside. If an older carb has been installed then you don't know if it has jets in it suited for a 360. And our current gasoline. They have an identifying number stamped on them. When you get the carb apart post what number jets you currently have. If you end up needing different jets and can't find them locally, I have some you can have.

 

I've always hated how the Autolite accel pump works. It is hit and miss and usually miss on any carb I've had. No matter how I cleaned it and kept it lubed. The Holley is always better in my eyes. But you know opinions.....everyone has one.

 

My bubbles are still intact. I've never seen a 1970 360 V-8 that didn't come with a bi-metallic spring for the choke pull-off. That choke arrangement, with the tubes that lead to and from the exhaust manifold, was implemented for 1970-72.

While I tend to agree with you, there are folks around this forum that wouldn't think twice about doing that. They wouldn't think of it as "aggravation", they'd think of it as "a fun project".

My suspicion is that the vehicle has been mis-identified as a 1970. Can you post the VIN, and have you checked the VIN on the door against the VIN on the frame?

 

I found something like this at a local auto parts store:

 

Well I guess it is not a 1970, but a 1972, with a 1970 front end. F10YKP64563 and the very last run of the bumpside July 1972.

Ya, I guess it is a conversion, although for the life me, don't know why anyone in their right mind would convert back to a manual choke if you had a good autochoke.

BTW, where is the VIN on the frame, don't know if I have seen a reference to that ???

Thanks !!!

Michael

 

It is located on top of the frame rail under the passenger door. There is also the sticker under the door striker if it is not faded or cracked.

 

360 CID V-8 for 1972 also came with the Automatic Choke.

VIN is stamped into the top of the right frame rail in two places, both of which are really awkward to read. The frame rails tend to collect gunk (which can obscure the VIN), so a brush, scraper and maybe some solvent is called for, You'll likely need a light and a mirror to read them.
Look at the top of the rail near the alternator and the top of the rail below the seat (under the cab).
There isn't much clearance for the spot beneath the seat, seems a little easier for the one near the alternator.
I've recently been working under that part of the truck and tried to locate the frame VIN by touch, but with no luck

If you have a 1972 with a 1970 front end, I can't help but wonder if the truck was rebuilt after a collision, possibly with a mishmash of whatever parts were convenient. I'm curious to know if you have the '67-'69 -style sun visors or the '70-'72 sun visors. Having a '67 -style rear view mirror (with the integral '67 -style sun visor bracket) implies a '67 cab, which would explain the hole in the dash for the manual choke control; if it's the original plate on the door, it's possible the door(s) from the original truck got installed into a replacement cab.

 

Hi Thipdar,

Well thanks for the reference on the frame, was able to identify the Frame Vin is the same as the metal tag

the Vin sticker in the cab was painted over, so I couldn't use that as a reference.

I had another 72 to compare to, look identical, except for the grille. I suspect (2) things, original 72 grill got

tired and the PO probably found a good used 1970 one and put it on and for whatever reason was not a fan

of the autochoke bore a hole in the dash installed a manual one, dunno. This one originated in Kansas City,

so it could be given the extreme Winters and Summers of KC the manual was a better fit, so you didn't have

to make that 3 to 6 month adjustment on the bimetallic housing.

Michael

 

 

Checked carburetor, like several of you have said, it is a pre 1970 Motorcraft 2100.

Took a look to see if there were any tags, or identifying marks on carburetor, could not find one.

Venturi's are in tact, no melty, melty.

Any guidance appreciated !!!

Michael