I am alsmot done with my TFI to DSII conversion on my 84 F150 2WD 300 I6. I however can't figure out where to plug in the vacuum line from the distributor. Does it go to the carb, carb spacer(or base), or to the actual intake manifold?

The carb I am using is the TFI carb, which I will unplug,( except for electric choke)

IF anyone has PIC, that would be awesome.

PS,I also posted this in the under the appropriate truck forum, if this looks familiar.

If it is advisable to go to a different carb, I am open to recomendations.

 

In most stock applications it will go to the ported vacuum port on the carb. Is this a Carter 1 barrel?

There are also some factory setups that run to manifold vacuum; typically those configurations use a relatively low initial timing specification.

 

fmc, it a 1 barrel feedback carb?

 

Later model Carter 1BBL carbs were available in feedback form; yours could be. Do you see a lot of wiring on it, besides a choke and throttle solenoid?

 

short answer is to hook up the VAC line where ever it idles the best

here is a link with info

http://gofastforless.com/
look at ignition curve... near the bottom of the article.

Stock installation will hook the VAC to the carb near throttle plate BUT the source is really above the throttle plate so no VAC at idle.

I just bought a Dura spark dizzy for my 86 F150
I plan on using the GM HEI, not the duraspark module

 

What JimsRebel said. And it might be productive of better results to scrap the feedback carb and back up to an older model too.

 

I took off my feedback carb over a year ago (it is still setting on a shelf in the garage) it was running rough at idle. I could look down the carb when it was running at idle and see an extra stream of gas going down the carb throat that wasn’t suppose to be there.
I just put up with it this way for many years before I found a (new old stock) older carb on eBay and installed it last year. It idled nice and smooth and I was happy.
It was only after reading online forums that I realized my 86 F150 I6 300 had a computer which also controlled the ignition timing. So I hooked up the timing light last week and found out my timing was about 12* BTDC regardless of RPM. Might be why I only get 12 mpg. So I have been collecting parts for the conversion. Went to a self service junk yard, that was really a waste of time as they wanted $25 for an electronic distributor, didn’t find one and if I did it would have needed to be rebuilt anyway. I did just buy a brand NEW distributor on eBay for $50, still 4 more left if you need one. It came with a cap and rotor for that price but I don’t think it was a “copper” cap and rotor, will see when it gets here. I did buy a fender mounted Duraspark module off a Ford Ranger and the complete wire harness while at the junk yard but I am not sure if I am going to use it as the GM HEI idea seems the best to me.

1986 F150 4x4 I6 300 ci, 3.50 axle with 235.75.15 tires

 

i've seen alot of carter yf carbs for *****'s floating around. Will these carbs mount up to factory manifold, or no go? What should I look for as far as an older carb??