Hesitation at 3000rpm

kenjrduster said

I bought a '70 Duster and can't get it running right. No papers and other info available. It's got a 383 bored out 30 0ver and stroked. Full roller top end with a wedge intake. Topped off with 2 4bbl holleys. I had to put a new MSD distributor in it to get it running. I opted to go without the vacumn advance. Now the problem is how to set the advance correctly. It boggs out at about 3000rpm pings little too. It's got fresh 93 octain in it. This isn't much info but any ideas would be appreciated. Thank You..

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Automatic? Manual? What's the stall if auto? Rear gears? Initial/total timing? Which port are you using for the vac advance? Full manifold or ported? Cammed? Any idea on duration/lift? What's the idle vac?

I'm far from the most knowledgeable, but the information you've provided is too sparse to even make a guess. It could be spark, it could be fuel, it could be a vac leak or too low a stall on the converter (if auto).

Could be a lot of things. In my experience, a wideband oxygen sensor and gage is a HUGE tuning aid. I use an innovative MTX-L. It's rather inexpensive and can help identify lean/rich spots in a hurry without much guesswork. If you don't have all the specifics, it can be even more useful. A vac gauge can also help to see what's going on under the hood when it bogs/pings.