vacuum diagram for 292

[292cclb]

hey everyone, i have a 77 chevy crew cab with a 292 1bbl. i had the carb rebuilt a couple months ago, not sure if it was done right. has'nt been running right since.i was wondering if anyone happened to know where the vac. line from dist. to the carb goes on the carb? it wants to run rough when first starting it up and then smooths out. also when i get it up to 50-60mph and let off the gas it just slows down fast. don't know if any of this has to do w/ vacuum or maybe timing. sorry so long, any help would be appreciated. thanks

[rwolf9653]

If nobody answers by the time I get home from work (8:00 pm est), I will look at my 66 and see where the line comes off, but I do not know if it would be the same for your 77.

[292cclb]

thanks rwolf. i'm not sure the year of the eng. because it orig. had a 454. it's rochester monojet,if that helps.
when i got it the vac. line was on the pass. side of carb on the top of the 2 ports. after rebuild it was on the dr. side on the bottom of carb. thanks again

[70inline6]

Distributor vacuum should come from ported (above the throttle plate) vacuum. If it was on the other side before, you could just try putting it back and see what happens.

Put a vacuum gauge on the ports and test at idle and at part throttle. If it has ZERO vacuum at idle, that's the one you want for the dist.

Some tuners will say with "X" amount of timing and this-and-that, you don't need ported vacuum... etc, etc... but for an every day driver, ported is where the factory put them.

[292cclb]

thanks 70inline6, is the port thats above throttle plate the one at the bottom of carb on drivers side or at the top by the air cleaner on the drivers side? thanks again

[70inline6]

Not sure. I have a Carter carb (non original) on my 63. I'm unfamiliar with the monojets. As I said, put a vacuum gauge on each port. If you find one at 0 at idle, that's the one you need.