Can I warm the car up first, then do this? Just so it starts easier and I can get to the fine tuning quicker? I would love to get that gassy smell to go away while idling. The wife would, too! I have to start it and idle it in the garage (attached garage) and it gets stinky in the house sometimes.
Cool. Getting new tires for my truck this morning, then I will get on those idle screws and see what I can accomplish!
600 Holley DP here. Ran great on the 302, runs equally great on the 351. I might try a bigger one out eventually just to see if it's any better at WOT, but probably not any time soon. It's not a race car, so why mess with a good thing? ...Side note, I also had a 600 Edelbrock on that 302 for a long time before I got the Holley. It too ran great, but neither carb lived up to its potential until I tuned it.
Finally got a chance to get out and do this, and I have to say...."THANK YOU!!!" No more fumes in the garage, and also "blips" better from idle. It used to bog just a 1/4 second when you I blipped it, but now it just immediately revs up like it should! I originally had all 4 idle screws around 1 full turn out. When I turned the 2ndaries in all the way, the engine faltered and died. So I went 1-1/2 out on both primaries and it ran good, tightened them down to about 1-1/4, still blipped well, but with just a very slight hesitation, so back to 1-1/2 and left it there. It brought my idle up a bit so I used the idle screw to drop down to 700 rpms at idle, 600 in gear. Thanks a bunch! No I won't feel so motivated to buy a fuel injection setup!
Your motor would be happier with a smaller carb, the 750 DP is way too much for your build. If you want mech secondaries, find a 600 DP and try it. Me personally, I'd go with a 570 Street Avenger on a 302 and install the lightest secondary spring, this will allow the secondaries to open a few seconds after you nail the pedal.
Mine even starts better when cold. When engine is cold, not air temps. Won't be able to test that for several months.