1973 B3 Duster

OK, Im glad you responded and have made some progress. So heres a couple of tips; (1)Theres a second reason for drilling those throttle plates. It allows you to close them down and still get a good idle and this properly locates the advance port so it wont activate at idle. Even my little 223* cam required these holes, so dont be afraid to drill them. (2) On the advance systems; this is very important; WOT timing must be limited. With adequate octane, the iron-headed sbm seems to make best power at 34* to 36*. A cam of [email protected] intake and a M/T likes initial timing of about 15*. (My motor gets a little jumpy in gear at or near idle at 18* which requires me to ride the clutch). So..35-15 =20* mechanical, is a good start point. I have found factory distributor cams from 15* to 25*.There are probably many others. If you dont have a suitable cam in your dizzy, you will need to modify one. Or some aftermarkets have adjustable stops. After you get the timing and idle-mix sorted that engine will smooth right out. (3)Vacuum secondaries and small rear tires are a good match. I have fit 295s and 325s to the rear so I can use a double-pumper. Still blows the tires away if Im not careful. (4) As to the 87 octane; My sbm has aluminum heads. On the street, I perceive little-to-no power difference with timing from 32* to 36*. So I just set it to 33*ish and let er buck. Its been working for me for over 100,000 miles. At the track I put in the good stuff and crank it to 36* Goes 93mph in the 1/8th. Fast enough for me. (5) Just to reiterate, you MUST limit your WOT timing. Not doing so can be very expensive. -------Hope you can make use of these tips. I had to learn the hard way, as no one around here could help me. After I learned I had many visitors. Im glad to share. Cheers, AJ.