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The place for the ported vacuum is just a hole, not sure if is operational, here are pics of the old and new
carb, anyone know where the ported vacuum fitting for the distributer vacuum hose should go? the port near the throttle pivot is missing, as you can see, I hooked my dist. vac. hose down below old carb, tube is there, and dist was connected there.
It looks like you got a 83> feedback carb and not the later type. That is why I tell people to look for one for a 81 300 six motor as we know that is non-feedback
Feed back = no vacuum for the distributor.
You can run it without vacuum, plug the supply, it might just be a little doggy is all.
Now if you are looking for something to do you might try and drill that out and see if it gets vacuum.
It is does you can geta small tube and drive it into the hole you just drilled and hook the hose to it.
Use grease on the drill bit to catch the metal shavings from going into the carb. If you cant get vacuum, remember you have to have the RPM above idle, you can just put RTV or a small screw with RTV in the hole.
Dave ----
There won't be any drilling going on, We have done some extensive research on the ported or non ported
vacuum advance, the only difference is at idle. I am going to run the vacuum from the vacuum tree under
the intake for now.
There won't be any drilling going on, We have done some extensive research on the ported or non ported
vacuum advance, the only difference is at idle. I am going to run the vacuum from the vacuum tree under
the intake for now.
Well factory used ported vacuum that does not effect the idle till you give a little throttle and that port then gets vacuum.
Yoi are going with manifold vacuum and that is fine, I have never tried that and maybe I should on my truck as I get pinging more so when pulling the trailer.
They say going with manifold vacuum that when under load like pulling the trailer you loose manifold vacuum and no more advance timing.
Let us know how it goes.
Dave ----
I watched a video by Tony I believe it was, and he went al lthrough the ins and outs of ported vs non ported.
He showed where the port was in the carb, and also showed a vacuum gauge as he drove and at idle.
Once the engine was off of idle, there was absolutely no difference between ported or non ported. He
recommended ported due to the poor performance off of idle I believe. Can't remember. I'll surely add to
this post if I ever get this truck on the road. I am very close, I believe. lol
I know this has been a "thing" for a long time and all I can say is give it a try both ways and see what works for you.
I am old school and have a hard time going to manifold vacuum for the distributor vacuum even just to try but I should on my truck just to see
Dave ----
