Make sure the vac advance hose is disconnected.

 

ya ima check my carb i think the problem lies there. also ported vacuum doenst help me much right now i dont know why but it ran better on manifold vac.

 

What was it doing while on ported vacuum, were you still getting a bog?
Ported vacuum generally doesn't alter the advance at idle. From the natural vacuum draw of the carb, ported vacuum increases as the throttle blades open. That increases your timing advance at low to moderate rpm's. Then at around 2000 rpm's, the MSD's vacuum advance can drops off and the centrifugal weights take over.
Hooking advance up to manifold vacuum advances the timing at idle. But when the throttle blades open, manifold vacuum drops and your timing advance will drop off too, until the weights pick it back up at 2k rpm's. So what you get is advanced timing at idle, advance drops off at low off the line rpm, then climbs back up again. That's one thing that gives you an off-idle bog/stumble.
See if this helps any: http://www.setyourtiming.com/Timing_...#VaccumAdvance

 

ok. well ill play around with both ones. its not a hard thing to change. but. i might have found my bog problem too.

back when it was running bad before i redid some of it. i adjusted the pump shot bolt out because it was flooding it out due to haveing half the engine running with a half closed hot air pump and crap exaust manifold and all this bad setup. anyways. i noticed the other day my pump shot moves maybe 1/8th of an inch before bottoming out... i also had the idle mixture screw turned out 1/2 a turn before bottomed out back in the day. it was set up running fine but it was a dog cause of the bad stock setup that i got it with.

now i got headers and all this better stuff so its breathin and pullin more fuel its out at 1 turn now. cause a half turn wont even start over. but now i think my pumpshot stopping at the point it starts bogin might be the problem.

went to my parts store got the measurement on the pump shot arm and bolt so i can tighten it up to the right length and tune it in a little after. i was gona go check it now.

also got more vac line and clamps for it so ill let you guys know how tuneing the pump shot goes

 

The arm on your accelerator pump should be set so it's zero clearance at idle. Should not have more than a few thousandths clearance. After that it doesn't matter much, as once you step down on the throttle it will give a squirt, and nothing more is needed. The size of that squirt is determined by the accelerator pump size in cc's.

 

so just tighten it up to 0 clearance.? yeah mine was set so it had almost half or more of the whole diapham pressed in.

 

You're still running a Holley like the one in your video, right? Because in addition to the accelerator arm gap adjustment, you can play around with the plastic accelerator cam. You can unscrew it and move it to two different mounting holes, or put on different cams altogether. All that is to change the ramp rate and the total amount of pump travel.

 

yeah. i know all bout the cam and the pump nozzles. but the second i started tightening that bolt down the better it got! i found an article and finlay understand it. how u have 0 clearance at idle. but at wot. there should be .020" of extra movement before bottoms out. mine was not even close so ima go tune that and see how it is but yeah. here i think that my timeing was the problem which im sure in one hand it kinda was. but my HEI will defintly pay off with better milage and so on once i get the carb tuned in.

tomorrow ima increase my plug gap from .040" to .050" stock HEI is .045" and MSD sight said this:

As an example, if you normally would run a .028 inch gap on your spark plug with a stock ignition, you could run a .032-.034

thats a .004~.006" increase so it should be good at .050"

also wanted to say thanks for helping me out so much. and all on 1 thread. you guys rock and have really helped me with my troublesome 305.

 

Lemme address the distributor on one more thing. If you find that your engine is responding better having manifold vacuum hooked up, the by all means leave i there. I wasn't trying to say you should have it hooked up to ported, only it would be something to consider if that's the source of your bog. Some engines actually respond better to manifold vacuum. And depending on the engine, there can sometimes be no difference in the amount of vacuum between the two. We're only talking about a vacuum advance operating range of between idle and 2k-ish rpm's, and manifold vacuum doesn't drop off to zero as soon as the throttle opens. I hope I wasn't making it sound that way, I wasn't.
For your plug gap, bigger isn't always better. And your mathematical theory of increase isn't necessarily a good rule to follow. .050 is too much gap, and honestly I wouldn't go much past .040~.045 on yours. I remember reading a while ago where GM first recommended .045 gap when the HEI system was newly out, then found that the engine performed better when they closed the gaps back down to .035. Keep in mind though, that's for a stock engine. So you can experiment with yours and start out at .045 and see how it performs. I have the plugs in my 69 set at .045, but I also am running an MSD ignition box.
Here's some good spark plug tech info: http://www.centuryperformance.com/sp...ch-spg-26.html

 

yeah mines at .040 right now. it snowed cant take it on the street to feel how the new dizzy and now accelerator pump work together but i will try to tomrow drive down the street and see how it goes. i might go to .045 and see how that feels then play around some. over the time.

i adjusted my pump to have 0 clearance but have about .020" gap between wot and bottomed out accelerator pump so hopefully it works out good. i understand how that adjustable cause different cams will make the arm react different and you must tune that bolt for the different cam shapes