I was driving home yesterday from dinner and as I stepped on it to pass a yellow light I heard a really loud click and the car seemed to stall for literally half a second if not less and then came back to life perfectly normal with no popping or other strange hesitations.

I was driving at 30 mph in 4th gear with a 4.10 rear end. My rpms were around 1150. This isnt the first time something like this happened but it seemed to happen under the same conditions. Low rpms, high gear, and sudden acceleration. I have a feeling I am flooding the motor for a split instant. However, my idea does not explain the loud click.

Even a guess would be helpful. I'll accept any opinion on this problem....

your car could be back firing up through the carb maybe? my car when cold will do this every once in a while. what carb are you running? is the car running rich? so you smell gas when the noise happens?

Downshift, you're lugging the engine at 1150.

yeah that or you need valve lash adjustment... do you have hardened seats?

Sounds like backfiring out the carb. Usually happens if it's a little lean. When you open the carb fast, it needs a bigger shot of fuel to catch up the air your adding. Once the fuel catches up it comes out of the bog and takes off. Could be accelerator pump in the carb isn't working, or needs adjustment. Thats my guess!
Steve

do you have hardened seats?

please explain what hardened seats or lack of have to do with this? :)

What rear end is it? Does it have a locker in it? Just thinking maybe it gets locked while cruising and when you tip into the throttle it gets loaded hard and then the locker disengages? Where you going around a corner when this happened? If so, and the rear was locked, it could load the motor. I realize this is a long shot but I have heard very loud lockers before. Just a guess.
Bill

don't rule out "pinging" at a low rpm if you are lugging in 4th gear

your car could be back firing up through the carb maybe? my car when cold will do this every once in a while. what carb are you running? is the car running rich? so you smell gas when the noise happens?

No it does not seem to be running rich at all. I check the fuel level all the time. I am running a 600cfm 4150 holley up series. I did research and found out that the carb is not the size that I was told when I bought it. But nevertheless it was for a steal. I don't smell gas but I do smell something burning for a slight second.

it's a 4.10 rear with posi track. 10 bolt. What exactly is lugging? I get the general idea of it but I don't understand it fully.

I was thinking about just upgrading to a 750cfm edelbrock and hope that it will solve that "lack of gas" problem with the 600cfm. Most of the responses seem to have pointed to that. But is it possible to buy too big of a carb? If so would I be able to buy the 750 and if its too big just replace the jets to something smaller?

?

Doubt you need a new or bigger carb, here. The lean backfire problem can be taken care of by tuning. Get a book or manual on your Holley and find out what specific adjustments need to be made to increase the accelleration pump shot or make it come in quicker.
This is a learning project, part of tuning you car to run better.
here is the formula for sizing:
CARB CFM = Cubic Inches x Max RPM's / 3456 x VE% - VE is Volumetric Efficiency roughly 75 to 80% for a street engine.
Preview of a useful book that should be in a tuner's library:
http://books.google.com/books?id=tGFlCg4ftkkC&pg=PA55&lpg=PA55&dq=CARB+CFM+%3D+Cubic+Inches+x+Max+RPM%27s+/+3456+x+VE%25&source=web&ots=SJHPUZ5RCa&sig=uW9hkE3YFv7VDxvOsZsiuT9jMNg&hl=en&sa=X&oi=book_result&resnum=2&ct=result


Without driving it, it sounds like a definite case of lean backfire.

Lugging is trying to pull the engine hard when its at a lower rpm range. I think it may be pinging which means the timing is too advanced. It will ping the worst when you are at low rpm and try to accelerate hard. Instead of just putting your foot into it, try downshifting, the engine will run better at a higher rpm. Its not designed to pull hard like that right off idle.

So it would be ideal to be in third instead of fourth around 30-35 mph?

If you are looking for quick acceleration, Yes.