First of all, it’s not as easy as slapping the carb on there and cruising. Job number one is to verify the timing. If your timing isn’t correct right off the bat, nothing else will be correct either and you’ll be chasing your tail. That engine has vortec heads, so your timing number is 32 degrees total timing. That distributor has springs in it that allow the full advance of 32 degrees at 4000 rpm, which is too high for a daily driver. You want the full advance to fall between 2500-3000 rpm. Get the spring kit from Crane Cams and use 1 blue spring and 1 silver spring, and that will allow full advance at about ~2700 rpm. Everything else about that distributor is perfect for that engine, just take the blue cap off of the vacuum advance canister so it will function. Easiest way to set your total timing is to pull the springs out of the distributor (be careful, don’t lose ‘em) and just rev it to around 1500 rpm and set timing for 32 degrees. Without the springs, the weights will swing out fully at low rpm, so you won’t have to run it at 4000 rpm with your head under the hood lol. After the timing is advanced to 32 degrees total, put the springs back in and you can move on to the carb.
There’s 3 things you need to buy when installing an Edelbrock carb. First thing is either a fuel pressure regulator set to 5.5 psi or a fuel pump that produces 6 psi max. (like the Edelbrock fuel pump). Edelbrock carbs flood with any more fuel pressure than that. Also, adjust your float levels to the specs in the instructions, or they will make the carb flood as well. The floats are never set correctly out of the box due to shipping and handling. Secondly, you need a heat insulating gasket between the carb and intake, like the Edelbrock 9266. Edelbrock carbs are notorious for percolating fuel after engine shut down, which causes hard starting issues. A heat insulating gasket will cure that. Third, you need the Edelbrock 1487 calibration kit to properly select the best rods, jets, step-up springs, etc. for your engine.
Once the engine is timed correctly, pull the carb off and the transition slots need to be adjusted next. Here's a link to a great thread from Gregski that shows the transition slots:
http://67-72chevytrucks.com/vboard/s...=713728&page=2. He begins to talk about it on post 37 and the following posts. The whole thread is worth a read, especially if you decide to go back to the Holley. After the slots are correctly adjusted, do not really use the idle adjustment screw anymore, as that will undo the work you just did. Slap the carb back on and set the idle mixture screws, with a vac gauge, for highest rpm. Ensure the vacuum advance and vacuum gauge are plugged into manifold vacuum when you do this. Turning the screws clockwise leans the mixture, turning counter clockwise richens it. Turn the screws all the way clockwise to bottomed out, then back out 1.5 turns, and start from there. Here’s a good video from Jegs outlining the setup:
https://www.youtube.com/watch?v=wR_AfQjyT-A&t=3s.
As everyone else has pretty much said, and as shown by rharris’ picture, the back of the intake needs a connector with 2 or 3 ports on it to supply manifold vac. The trans modulator needs to be connected to that. The brake booster connects to the rear port on the carb (make sure the check valve at the booster is good and not leaking), PCV hose on the front large middle port routed to drivers side valve cover (not sure if it truly matters which side), cap the ported/timed port on the passenger side front because you have no need for it, vacuum advance plugs into the driver’s side port. Next, go for a ride!
10-31-2019, 08:43 PM
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