Hey i have a 305 and in the next 6 months i will be taking the car apart and installing a 330HP 350 W/Vortec heads, My question is i want to fix my carb now because it is running bad and it is $200 to fully rebuild and rejet it, Would it hurt to get it fully setup for the 350 now while it is getting rebuilt and drive it on the 305 for another 3 months before i take it off the road to start tearing it down?
Wouldent it just give the 305 a little more ***** at the expence of less MPG?

 

The tune should be close enough to run your existing 305 without much problem. Expect to have to readjust the idle mixture screws and idle speed screw when you throw it on the larger motor later- the idle is the thing that will be most different between the two. The jetting should be plenty close.

In any case, a properly functioning carb, even if not set up perfectly for your existing motor will still run a lot better than a carb that isn't functioning properly to begin with.

 

Cool that is what i thought, i know how to adjust the carb, its easy enough.
Yeah at the moment i lose power before 3,800RPM and a have a slightly bent throttle shaft so it sticks just above idle.

But you got to expect these problems with a 40 y/o carb

 

Since when?

A kit is about $25; jets are about $8 a pair.

I don't have any clue about this "fully set up for a ..." business. A carb can't be properly "set up" until it's on the engine it's going on, in the car it's going into, with the transmission and rear gears behind it that it's going to spend its life in front of, with the driver driving it that's going to be driving it. I can't imagine how anyone could EVER possibly duplicate that. For a race car, yeah, IF you know all that going in; for a street car, no way.

Rebuild your carb. If it's not perfect, figure out if it's too lean or too rich, and buy a couple of sets of jets accordingly. Here's a hint: it'll be too rich, and the power valve number will be too low. Stock Holley setups are JUST ABOUT ALWAYS like that, because they assume that the carb is going on a motor it's too big for with too much cam; and if they set it up that way, it'll at least run, if not optimally. Whereas, if they set it up for a well-built motor with a properly matched carb and then it got stuck in the usual hot-rod situation of mismatch as described above, it'll be TERRIBLE.

First step though, is to rebuild it. Go get a kit and a gallon of lacquer thinner and go to town. Then come back and tell us what it does, and we can point in the direction of what to do next.

 

Ok a kit for a Holley over here is around $50 coz i put one in it about 4 months back but is has a fuel leak from both sides of the throttle shaft, it also has a slight bend in it so it sticks at about 1600RPM, Both idle mixture screws are in all the way and it runs ok, but if i move them out it gets REAL ritch and stalls.

I duno, I just think it is best done by an expert.
(will be watching while it is being done, that way i know how to do it).