I have a 78 ford 351m, I have just replaced the stock 2bl intake and carb with an edelbrock 400 performer and an 1406 carb. The problem i'm having is what vacuum lines are nessasry to keep, cause i was left over with a few that now don't go anywhere . I just caped them untill i can figure it out. I'm sure that this has been asked a 1,000 times. I tried looking but there was no online referance that i could find about the swap from a 2bl to a 4bl. Does the distruber vacum advance go directly to the dist? Also my Air pump has siezed so i just took the belt off. I want to take all the egr and emissons crap out. if any one can help me that would be great. thanks guys.

Jonathan

 

As long as you don't have to go through DEQ the only vac lines you may need are the manifold vac port for the brake boosters and a metered vac line for the vacuum advance. Again if you don't have DEQ where you live you dont need the air pump, it's just more parasitic power lost. On an edelbrock you can tell wich port is metered vacuum because it is small and will be just above the manifold vac line wich is larger. The vac advance will go straight to the distributor.

 

Having an EGR will rid the engine of pinging .

The V/A requires Ported vacuum.

Vacuum hoses are required for

Brake Booster (large one)
Auto trans
To Vacuum reservoir (if truck has AC or Speed control)
Dist ...V/A

 

hey guys, thank for the post,

All i have in the truck is the V/A, and auto tranny,

I do have an air box where vacuum lines go to but i just pluged that. they are also lines that go to the water neck?? I'm going to look in the manual and see if i can figure that one out.

So the way it goes, just plug tranny and V/A from the vacuum treein the back of the manifold?

Also the old carb had the (what i think is erg) old line from the drivers side valve cover bathle, i just pluged that into the front of the carb. Is that correct. I put a clear line, and there is not much oil coming up. Should i just put an oil cap on the valve cover?
Thanks guys, i really aprechaite it.

Jonathan

 

Vented oil cap on the valve cover.

No Brake booster ?

The VCV on the T-stat housing is a switch that redirects vacuum to the V/A

Ported vacuum source on 2150 IIRC, is on the passenger side front side