My '72 340 is a transplant into a '90 Dakota and I'm not sure all the vacuum lines go where they a supposed to. The engine has a Eldebrock Torque 340 intake manifold and a Carter AFB 4 brrl carb. Can anyone direct me to a diagram or something to that effect that may show the correct terminations?

Thank you
Joe.

 

Joe -

Depending on exactly what's under the hood, the two large (full) ports go to the break power booster and the PCV valve. There should be a ported vacuum going to the distributor. That's all that's "required", anything else would go into the accessory category. If not used, they need to be plugged.

Archer

 

One more thing to add to what Archer is saying. I'm not completey sure but I bet they were using vacuum motors to operate climate doors for say defrost, floor and vents in 72. Look for something about the size of a softball maybe slightly bigger probably tucked in the fender area on the passenger side of the car. Could be towards the fire wall or up front by the head light not really sure but if you find it, it needs manifold vacuum to operate.

 

Unless your running all the smog **** on this 340 motor manifold vac to the distributor advance is the only way to go ..... yes opening myself up to the age old debate over ported vs manifold, just going by experience and what I was taught

 

Thanks guys, sounds like I'm okay.
There is a large hose coming off the manifold below the rear of the carb that goes to the booster, from there a very small diameter hose that goes through the firewall that is labeled heater.

In the front of the carb center there is a large hose going to the pvc valve.
I did some reading on the carb it's self and there is two small ports one left and one right of the large one in the center. The one to the right is tubed the vacuum advance the one to the left was described as to be used with smog control stuff, it's plugged off.

The engine is running a lot better with the new distributor (vacuum advance was shot) but with out that darn timing pointer I can't be sure the timing is set correctly. I can set the timing at idle that makes that engine sound so good it makes me drool listening to it, take it out on the road and it backfires through the carb.

One other thing that is bugging me is the PVC valve is opening and closing so fast at idle you can hear it and feel it vibrating.

When I think off all the fun I have been missing.....

 

Ya need to get a pointer on that motor and know the base timing is right, guessing on timing can result in **** happening that you dont want, and it sounds like yours is off and or the fuel mixture is lean - PCV is stamped with a number (most) this is the vaccum it opens at, yours might be wrong or just crapped out .... crunch some #'s dude

 

Okay, that settles it then, no more goofing around!
I will get the pointer and the base timing set before I do anything more.

It's just like me to get impatient and screw something up that could have been avoided.

Thanks for the advice.
Joe.

 

Last thing you want is to damage the top of the pistons, carbon collects quick and makes hot spots which will cause preignition or you can burn a hole through the pistons and that will cause you to be walking not driving .... knowing your base timing is very important so get the tab before its big $$$$$