Vacuum reading help.

sfvaliant said
Were you ever able to figure out exactly what was the carb issue?

Previously, I had tried rebuilding my carb(s), and bought at least 3 rebuilt carbs from auto parts, that I recall. This was over ~18 years. When it still idled rough after installing a rebuilt long block, I was upset. 2 years prior I had installed a different intake manifold, plus checked for vacuum leaks many times w/ propane. I also had a Crane XR700 electronic ignition. Broke down and bought another Holley 1920 and it idled perfectly with no more stumbling off the line - vroom - vroom like my Honda motorcycle used to run. The Holley 1920 has a sealed metering block, so I don't think any rebuild house can check those. The carb that ran great had a strange small hole drilled thru the side into the bore, like a CNC machine went crazy. I put a hollow Q-tip in there so it wouldn't suck in dirty air. Was that a fix? I have read the same about Holley BBD shaft wear, but that is a problem for most any carburetor.

sfvaliant,

I used the same GM 8-pin module that TrailBeast sells but got my parts at the junkyard for ~$15. If you do that, be sure you get the cable that goes from the module to the coil, which is easier than wiring your own as in TrailBeast's kit. Also snip off the GM pickup connector. A great time to also get the knock sensor and module. It screws in the block drain. For a slant, you just need a 1/4 NPT to 3/8 NPT bushing from Ace or Home Depot.