Vacuum line diagram for chevy 350 engine with 4 bbl holley carb

Fuel pressure, filter debris, fuel volume, carb not adjusted

I don't think your engine is a 22R-E as the E denotes electronic fuel ejection. For 1980 it should be just a 22R. I would not suggest slapping on another carb without expecting more work than just hooking up the original vacuum lines. Some lines you could cap off but others would need the vacuum and rerouting. There is plenty of info in the following blog on removing smog devices and extra vacuum lines here:
http://www.yotatech.com/f114/de-smogging-early-22r-205845/
There are also plenty of pictures and diagrams for your engine. Making a trip to your local junkyard might find you a 22R with a carb still attached but it's slim these days. I know this question is from January but if it's too late to help you than maybe it can help some one else.

the vacuum advance line will be connected on a pipe at the closed position of the throttle butterfly. The pcv valve hose goes into the manifold under the carby

1979 chevy C1500
the vacuum setup varies,
by (california, Federal (USA) and export models)
where are you, or if in USA the under hood sticker shows if calif.or not.

if in usa, use the FSM (buy one used) or use alldata.com
on USA cars , (not sure starting year, this one is old) the vacuum
map is on the underside of the hood. (not not painted over,etc)

Check this diagrams for 1985 Chevrolet Truck G30 1 ton Van 5.0L 4BL 8cyl (click over pic for zoom)...



Fig. 123: 1985 5.0L and 5.7L engines-Federal with automatic transmission (G10, 20 and 30 models)



Fig. 126: 1985 5.0L and 5.7L engines-California with automatic transmission (G10, 20 and 30 models)

Hope this helps.

Most likely you have a Holley carb. You may have a 460 engine. If you have the carb with a big vacuum pot in front of the carb, then you have a RPM governor. The RPM governor will work against the 4 barrel.

The main mixture for the idle jets can be adjusted like any old style carb. You may have plastic caps over the idle screws but take them off. Then use a vacuum gauge on any intake fitting and proceed to read the vacuum level as you turn the mixture screws. You want the mixture to reach a maximum RPM, then evenly turn the screw in until the RPM drops slighty and then balance for smoothest idle.

After this step adjust curb idle and see if this helps when the 4 barrel kicks in. Holley has different springs for the vacuum actuated secondaries and they are color coded. If the carb is original it should be right, but if the carb is of unknown origin you can check the proper vacuum spring, main jet, power valve and so on in a good Holley book. The mechanical secondaries are also listed with clearances to hand adjust.

By adjusting the mixture screws you have set the engine to idle just below peak vacuum pressure. This means you should have more vacuum to work the secondaries.

The jets in the carb are too big for a 302 with a stock cam. Take it to a carb shop and have them replace the jets with stock jets. (Or DIY and hope). Whne you converted from FI to carb did you replace fuel pump to get correct 7 1/2 psi pressure at carb inlet? FI pumps put out 50+ psi and a regulator maintians pressure at the injectors on the order of 35 psi.. Of course, that much pressure would force inlet needle valve out of it's seat and would probably flood carb totally, but, check the fuel pressure at the carb just to be sure. Good luck. 302's rule!!!!
PS - Check cam specs - FI engine has different cam - intake duration is longer if I remember correctly. Been a while since I got inside an engine...

try the "repair info" section at autozone.com or your local library for a Chiltons or Haynes repair manual

Most carbs need any where from 4-6 psi