i was wondering if you need all the spots on top of the gas tank where the gas lines go into it. i was told you dont

 

need? you mean like: "use"?
unless you have monkeyed with the rest of the lines and how they interconnect right up to the carb, I would think the loss of any one of the 4 lines would create some chaos in getting fuel where it is supposed to go. Why risk? just use 'em.
NOTE: very important to NOTE which lines go where so you don't mix them up. Found this out the hard way....

Stu Aull
80GS
Alaska

 

you need all of the lines. a feed, return, and vent are a necessity.

 

Only if you want the car to run.

 

are you doing custom work here? if so, you need three lines total but it is easier just to weld the stock ones shut and start with a weld on sump for the fuel supply then weld in a return about halfway down the tank preferably with a baffle of some kind and then the vent. However I doubt that is what you are plannnign.

 

Depends on your carb setup. With a nikki you need the pickup, return and at least
the vent. You can do without the one to the roll over check valve thingie but you
need to make sure your venting is working.

With other carbs it depends on whether you run a return or a return regulator. If not
then you don't need the return either.

So it all depends on what your doing which you haven't told us yet