My truck been running a bit rough at steady cruise just off idle. Last weekend after going to the drags it got worse and the throttle was starting to stick. I decided to pull the carb off so I could open it up and give it a cleaning. Once I got the carb off I noticed that my 1" phenolic spacer had shrunk up. This was interfering with the butterflies as well as giving me a vacuum leak.
Hopefully tomorrow I can get the new 1" aluminum spacer installed. Here's a couple of pics of the 2 spacers.

Bobby

 

Aha,I see what that ethanol does....or is that from heat?Not sure what carb you are using,but I've got an aluminum closed plenum with a vacuum port,like a Mustang-type.What does that fit?

 

I'm not sure what the cause is, probably heat. Thats from my stock Quadrajet carb on the factory Cadillac intake manifold.
This is one of those cases where you get what you pay for. Several years ago when I was in one of those "tightwad" moods I think I spent about $10 on that phenolic spacer instead of shelling out the $25 for the aluminum one.
Now I had to go ahead and spend the bucks....you'd think I'd learn.....

Bobby

 

Bobby,
You may want to use a thin (1/4") phenolic spacer with that aluminum one to keep from heat soaking that Quadrajet. I know I have one for a Holley, I'll see if I have one for a Q-jet.

 

I hadn't thought of that. If you have one that would be great. I'm hoping to only need it for the short term as I want to finish up and install my fuel injection this summer......well, ok, this fall

Bobby

 

Sounds like me.

 

Looks like it may have swollen up into the vacuum passages, too.

 

Bobby, what kind of times did you run?

 

My best time was a 15.7
I feel pretty good about it, 15's are nothing to sneeze at for a morphodite of a truck running at a mile high track. My first pass was in the low 18's....LOL I had too much adrenaline and smoked tires all the way into 2nd gear. After that I was able to calm down and focus a little.

I think if I were to tweak things a bit; play with timing, air pressure, etc I could probably get it down consistently into the low 15's.

Bobby