I have a 86 F150 300 I6 bored .40 over, new head and crane cam, Did the work about 6 months ago and it is running great, however, there was an issue with thermostats after boring it over, solved that problem after a day of troubleshooting. I put a new carb on when doing the engine work (Stock one barrel) i would like to upgrade the carb with minimum intrusion, dont realy want to split the manifolds again. I currently get about 10-12 miles a gallon, oh yeah the tranny is a c6 rebulit last year. I would like to get a little more pep and possibly better gas mileage. Is there a bolt on two barrel that would work without much modification? looking for some pointers and or tested and proven mods? well what say you

Joe

 

There are 1v/2v adapters out there but you would not be gaining anything and maybe losing since you have 2v feeding in to a 1v manifold. There are a number of performance upgrades that can be done and they have been cussed and discussed ad infinitum on this Forum. No guarantee that any of them will result in improved mpg though.

 

10-12 is a little low for a stock 1 barrel carb even if the engine has been bored; you should be getting 14-15. Sounds like your carb is running rich. I haven't seen any 1-to-2 barrel adapters but I have been told they exist, albeit being very expensive. I recently did the 4-barrel carb and intake swap; I am running an Edelbrock 500 CFM and get 15.6 MPG and I haven't even tuned it yet. It runs a tad rich, so when I dial it in I would expect it to go a little higher too. The bottom line is, though, that if you're wanting a gas saver, then a classic Ford truck is not the way to go. Like Harte said, a 2 barrel isn't going to help you any, if you're looking for mileage. Regardless what carburetor you put on there, you still have 300 cubic inches of displacement sucking fuel. My advice to you is to go through your 1 barrel carburetor because no carburetor upgrade will provide a significant mileage increase, except for a 4-barrel which will gain you 1 maybe 2 MPG. Like I said, you should be able to hit 15 as-is.

 

I suspect that you have the feed-back carb system. If so, every part of that system, the ignition system, etc., has to be in perfect tune and you should be able to get better mileage. Just a suggestion, you might try using the extended tip EFI spark plugs either Autolite or the NGK WR4-1 V-Groove that can be had on-line through Shucks for about $3.00 each + shipping and opening the gap a little on them.

 

Thanks for the input. I already figured I couldn't gain much in MPG, however it was worth throwing it out there. I do have a slight vacuum leak thru the brake booster seal at the pedal which mess's up the idle a bit, It is the feed back system and picky about how she idles. The cam I have pretty much doubled the lift and duration from stock. I was hoping in the long run I could upgrade the Carb and gain some performance. With the c6 it is realy more a torquer then anything else. Maybe the move to a 4 barrel and new manifold might do the trick. Being .40 over flat tops it does suck a lot of fuel but it sure pulls like H***. Any recommendation's for a sight to pick up the parts? well thanks again

Joe

 

I personally like Summit (Summit Racing - High Performance Car and Truck Parts | 800-230-3030); they have most of the stuff you will need. Really great people to deal with. I picked up my manifold, carb, air cleaner, and throttle cable from them. I had my throttle cable bracket made at a machine shop.

 

Summit sounds good. Do you have a Pic of the bracket? i could probably figure it out but if you had one it would save some time. Did you run into any issues with the tranny kick down linkage? I remember a big problem with kickdown linkage on a Dart i was rebuilding a few years back. it took some re-engineering to get it right. I wonder if it will be a problem here. Any input? thanks

Joe

 

eBay. Summit, Holley and a number of others have eBay auctions/stores.

 

Hi Joe, my throttle bracket was quite an interesting challenge because I am running a dual plane manifold on an AC truck. That means that the carburetor is positioned 90 degrees turned, rather than straight on like a conventional V8 setup. Many people run open manifolds, which lets you position your carburetor any way you like, so they can keep the carb in a straight-forward fashion and the linkage is much more conventional. My situation was unique because my carb is actually sideways, which wouldn't normally be a problem because you can still install a conventional throttle bracket and have the cable wrap around the carb. However, because of my AC box, I had zero room to pull behind the throttle linkage, so I had to pull from underneath on the other side and fabricate a special bracket. Below are all the photos of my project. I need to set up my user gallery sometime, so that I can keep these all in the same place.

A shot of the bracket with return spring retainer mounted:



Bracket installed: it bolts to the manifold with two through-bolts.



Closeup of linkage:



Shot of the other end of the linkage. I still need to replace the zip tie but it works for now.



Here's a shot of my motor. As you can tell, the AC box is pretty much right behind the carburetor and there wasn't any room to install a conventional throttle bracket that Summit sells. So I had to do pull from the front of the carb instead of the back. And to keep the throttle plates rotating in the same direction and since I was pulling in a different direction, that meant I had to pull from the bottom end of the throttle lever instead of the top.



Unfortunately with this setup I can not have a kickdown, since I'm using the kickdown spot on the throttle lever for my throttle cable. No more room. However, Lokar does make kickdown assemblies, but you have to use the "pull-behind" throttle setup as far as I can tell. Honestly though, it's not really a big deal because I can still downshift manually if I have to. Automatic kickdown is really just more of a convenience. But to tell you the truth, I found I have so much extra power now that I don't really need the kickdown anymore. Stomping on the gas and opening up those secondaries almost feels like dropping down a gear!

 

Nice engineering!

I don't have AC but the fit was tight to the heater box with my Holley 4360 and I used a Spectre bracket and Lokar 4' cable so I could pull from the top.

http://i144.photobucket.com/albums/r...Picture032.jpg

http://i144.photobucket.com/albums/r...1-17-07005.jpg

I have since changed to this carb:

http://i144.photobucket.com/albums/r194/Harte3/003.jpg

IIRC no particular problem not using the kick down on a Ford but there might be on a GM.

 

Thanks Harte; you did a great job on yours as well. Love the pics.

 

fmc400, that is a nice bit of engineering. I was considering the dual plane also. I have an 86 and a bit more room in the engine compartment. I priced both the single and dual manifolds and the price difference is not that much. Thats an interesting idea with the kickdown. I never looked at it that way. with the c6 i dont usualy kickdown much anyway. The cam I have is perfect and very responsive between 50 and 70 MPH. Next thing to look for will be the carb and headers. Once upon a time I was considering the Fuel injected exhaust manifold, however, I like the look of your headers, it matches the new intake and carb. I am hoping to do the manifold carb and headers for under a thousand $$. Cant waite to get the parts rolling in. Again great pics. On another note have you ever used LMC truck for parts at all? well be safeJoe

 

Thanks for the compliments Joe. As for LMC truck, they're good for miscellaneous odds and ends that are hard to track down elsewhere. A lot of their parts, though, are foreign-made junk. A lot of it is overpriced too. FTE has several site sponsors that often have better deals. For example I'm a fan of MAC's auto parts; I got my door panels and door glass guides from them. They've got a lot of handy restoration-type parts. A lot of that stuff can be found through LMC, but LMC tends to be a little more expensive. FTE also has an 80-86 F-series forum and the guys there will have a lot of info for all things related to that body style.

 

LMC is quite "proud" of their products.