I just swapped the 305 for a 350 in my 92 RS. I thought I was on my way to the maiden voyage today. On my way out the garage, I found I could not depress the brake pedal. Upon further inspection, I find a brake line that used to go to the "carb " on my tpi. It is a vacuum of some sort that goes to the "vacuum booster" I have a diagram of where it is supposed to go. I Don't have any vacuum ports on my Holley Carb. I am using the 750 dp. It is an older one. I am not sure what to do. I have my car's service technicians manual in front of me,but it doesnt really go into detail about what it does, or how to fix this.

 

There may be a plug on the back of the holley that can be removed so you can put a Vac nipple on to it. So you are saying that to your brake booster, the large vac line is not connected? If so, that needs a constant vac source.

 

I don't have a spot on the holley, any other suggestions?

 

[&:] should be a vacuum port on the manifold behind the carb, probably got a pipe plug in it?? most manifolds had one anyway kurt

 

[&:] done some lookin around i think it would be a very rare carb that didnt have a nipple in the front or a screw in plug in the rear, either can be used for the brakes.

 

Well I just went out and did a lil switching around. I had a vacuum line for the distributer on the plug in the manifold. and I took what was there and put the brake vacuum line there. and if it doesnt matter what plugs into the carb, I can put it back the way it was and hook the vacuum line to the carb. I just thought it had to go into a certain spot. I thought all the hole on the carb were for fuel and air. not vacuum hookups. So long story short, I have brakes, they aernt that great right now, but it is a start. Thanks guys!!

 

[8D] cj remember there are two types of vacuum on most carbs manifold and ported. if you run manifold to your distributor it will be working the opposite of what you want. sounds like you may have a low vacuum problem also possibly from your engine part choices. if you want good brakes there are things that can help with vacuum storage so you get full assist from the booster kurt

 

what are the things I should be looking for?

 

I hope you connected the vacuum hose for the dizzy to a spot on the bottom of the carb that was bellow the butterfly. That is not suposed to go to the manifold.
And if you feel you are not getting enough vacuum for your booster there are items like this that may help
http://store.summitracing.com/partde...p;autoview=sku

 

what does the vacuum line do for the dizzy?? I will play with the lines in the morning, and see if I can come up with a configuration the gives me the most vacuum. Thanks for the help. There are a ton of holes in , my carb, should i plug the ones I am not using?