Is it necessary to use the OEM plastic line between the manifold and dist pot or can I replace that with 3/16th fuel/vac line?

In other words, is there a reason for the narrow diameter OEM hose? The nipple on each side fits the 3/16th hose but I'm concerned that the narrow plastic piece in the middle is there to reduce or restrict the vacuum signal.

My plastic line is cracked and broken. I was able to splice in a small rubber piece but the entire thing is difficult to blow through. I want to replace the hose but finding the OEM piece could be difficult.

 

I would believe that if you have a thick wall hose that is not wimpy and subject to collapse it would be OK, not affixed with tight clamps, etc. But when you let off gas headed down hill, vac will spike, so you don't want it to collapse the hose.

 

I've wondered about this myself - was curious if the smaller diameter of the tubing versus a traditional rubber hose made for faster adjustments/changes in the vacuum advance. I'd bet I'm over-thinking it. If you don't mess with the plastic tubing, it'll last longer than rubber tubing - likely the reason why it was used and likely has nothing to do with vacuum signal.

I've read where plenty of people ditch the factory setup after the tubing breaks and pop on a traditional rubber vacuum line. I did a repair on mine which holds vacuum, so I ducked that bullet for now.

 

Copper tubing works like a champ with silicone/surgical tubing for the ends.

 

The Donor truck I had I used just plain old vacuum line for it, I got it small enough to fit with no clamps, seems to work fine.

 

Yeah, I use auto parts store vacuum tubing on my '95.

 

Thanks guys...just what I was looking for. I got some 3/16th fuel line (thick wall) from NAPA today. I didn't think it was much of an issue but no doubt they paid some egghead hundreds of thousands of $$ to come up with the plastic tubing...must have made sense to someone at the time.