tpsierra

Installing a M4MC carb from an Olds onto my 350, slightly different from Chevy (maybe more cfm, too). Has two ports on front of TB (pvc and ?), one 1/2 way up carb on left front, one 3/4 up on right front, one above that to choke unloader, and two on back center top of carb plus power brake at center bottom rear. Which is for vacuum advance, which is for rear choke unloader (and how activated), and can I plug all others?

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1966 c10 panel
1968 c20 350, 350
1982 camaro 305, th200

Damon

You will have to play it by ear. For the rear choke unloader you use whatever source of FULL manifold vacuum is available, just like the main one up front. For performance applications its easier just to completely eliminate the rear unloader (its PURELY an emissions thing).

Spark advance should be a PORTED vacuum source- only supplies vacuum once you are above a high idle.

PCV you should hook up to a PCV valve in the valve cover and keep functional. If you don't you will be wiping down the valve covers every weekend from the blow-by coming out of the vents.

Powqer brakes I'm sure you can figure out on your own. I usually eliminate the stock steel line over to the booster with a much easer to work around rubber vacuum line.

Whatever's left you can plug up if you aren't using it.


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94 Firebird Formula M6- No options but Z rated tires. No mods over $10. 13.5@105.
79 Malibu "beater" w/junkyard 400 SBC, tweaked QJet 4bbl, finally a decent set of heads, a few other tricks. A maddening 13.000001 @ 108 on the motor with little traction. No nitrous runs with the new heads yet.

"One of the last remaining QJet tuners on Planet Earth!"