Ive been trying to get some help with this motor but nothing yet. so this is what I have going on.I have a 81 bronco. the straight 6 blew, so I bought a 96 4.9ltr with 80k on it converted it to a carb, with efi exhaust manifolds. running an electric mr. gasket fuel pump, with a mr. gasket fuel pressure regulator at 3psi, if i run higher then that the fuel dumps out the carb(stock 1bbl). i think the carb needs rebuilt but i have a holley 2bbl carb I got for free its list number is 6855 I believe its a 2300 model? I need a adapter for it but dont want to spend $60 for a 2bbl to 1bbl adapter. dont have the money for the clifford or offenhauser intake yet can i get a cheaper one and where? another issue i have is vacuum lines im having a hard time remembering what went were and the diagram on the truck kinda sucks. what vacuum lines do i actually need that wont hurt gas mileage. i have the initial timing set at 10degrees which seems to work pretty well untill i hook up the vacuum advance then it struggles to go up hills and over heats. my vacuum diaphram seems to not adjust so i have another one that does but how do i know what to set it at? seems like its retarded now. if some one could atleast answer a couple questions i would be so greatful ive been struggling with this thing all summer.. thanks.
81 ford bronco, 96 4.9ltr converted to carb and c6 trans.

 

First thing that comes to mind since you asked about vacuum lines is do you have the vacuum advance hooked to manifold vac ( pulls vacuum all the time) or ported vacuum( no vacuum at idle)? Lets start there, should be ported vacuum.

 

rebuild kit for that carb is $18. it comes with a new needle and seat, which is what is wrong with your carb. I would not put a 2bbl on that intake, would just leave it stock until I put on a different intake.

 

yes sorry i forgot to mention it is on the ported vacuum. it idles fine when i plug it in to the ported vacuum but sputters horrible at 2500rpm and has no power over heats going up hills, soon as i unplug it, drives fine.

so running a 2bbl to 1bbl adapter wont help at all? i really dont feel like dropping $250 on an intake right now. so maybe ill just rebuild it then.

what about the vacuum lines is that mess of color coded wires needed? or can i just run vacuum to tranny, canister, fuel evap can,distrib, pcv. anything else?

 

I'd go on and clean/rebuild the carb as dustybumpers suggested. Make sure you have no vacuum leaks. As far as the vacuum advance, I have a 289 HiPo with a Duraspark that I never have figured out. It will not run right with it connected, but runs fine without it. I finally gave up and just plugged it at the carb. Someone more familiar with that engine will have to help you with the mess.

 

this is my 82, mabe it will help.

 

thanks man. not sure what some of the abreviations are though.

 

All the systems must function properly. Unplugging anything is not a fix for anything. If you are still running the EFI ignition it would probably be best to change to a DS2 system with the carbed set-up.

 

im not running efi anything except exhaust manifolds. its completely converted to carb. i bought a mallory ignition coil though cause mine was bad. i converted a newer motor to go into a older truck. how can i tell the difference between the ds2 and others? im not sure what mine is. its an 81 bronco.