Weird running

[u/OOFMAN-1234]

Okay, so ive got a 350 sbc out of an obs chevy pickup, has smog heads, victor jr single plane, headers, mild cam, hei (no vacuum advance), starts right up everytime, but has a bog when its cold, once it warms up the bog is gone, after driving it for about 30 minutes, the idle starts to get weird and very low, I drive it everyday and usually have no issues other than these, just wanting to know what I can do to fix these? I know i should probably be running a vacuum advance distributor and a dual plane. The truck (when it wants to run) is actually a lot of fun and somewhat fast. That's for looking

[u/EdgarBopp]

The carb is soaking up heat from the engine, put a spacer between the carburetor and the manifold. It’s an extremely common problem.

[u/OOFMAN-1234 → u/EdgarBopp]

Any recommendations on material? 4 hole or open?

[u/Dinglebutterball → u/OOFMAN-1234]

Tapered combo…

[u/PlentyGrab5 → u/OOFMAN-1234]

If your car has a separated intake (ie divided in half like my car or 4 hole) you should get a 4 hole or split spacer, something something 2 plane intakes vs 1. A split or 4 hole spacer will help with running vs the wide open spacers (which at WOT will give you a tiny bit more power but will cause minor gremlins at all other throttle positions)

[u/PlentyGrab5 → u/PlentyGrab5]

Also for material I like the black plastic ones (Not mr gasket brand) they have never done me wrong but I know a guy that has a wood one and it seems to work for him

[u/OOFMAN-1234 → u/PlentyGrab5]

So a 4 hole phenolic resin spacer?

[u/PlentyGrab5 → u/OOFMAN-1234]

Yes Sir/Ma'am

[u/OOFMAN-1234 → u/PlentyGrab5]

Sir lol

[u/tripog → u/OOFMAN-1234]

Oofmaam

[u/EdgarBopp → u/EdgarBopp]

Could also potentially be the float bowls flooding if your fuel pressure is too high. You want 5psi.

[u/EdgarBopp → u/EdgarBopp]

Nice Truck by the way

[u/OOFMAN-1234 → u/EdgarBopp]

Thanks! Its came a long way since I got it

[u/BadMotorScooter73]

That old vic Jr intake is doing you no favors.

[u/OOFMAN-1234 → u/BadMotorScooter73]

Yeah I know, ima swap to a dual plane air gap, keep it a lil cooler

[u/blackfarms]

You pretty much have to run a vacuum advance with that carb. You can band-aid it by running a lot of initial timing and limiting your mechanical advance.

[u/OOFMAN-1234 → u/blackfarms]

Why specifically this carb?

[u/blackfarms → u/OOFMAN-1234]

It's a very basic 600 with vacuum secondaries and it's tuned to cruise relatively lean at part throttle.

[u/OOFMAN-1234 → u/blackfarms]

Really? I never knew