Just getting my coupe and wondering what the dual exhaust manifolds were worth these days?

I old one to a speedway boy recently for his sunny.... $400

What's a dual exhaust? Is that the factory cast manifold?

Standard 1000 coupe and gx 1200's had dual outlet exhaust manifolds. Flowed better then the single poo ones

flow better than all aftermarket headers as well except professional systems by A series specialists
hence the GX and Kb10 manifolds command very high premiums, the hot cast iron helps keep gas flow up

What flow difference is there between the gx and kb10 manifolds?

for a street engine the heat riser improves fuel atomisation
so the Kb10 unit is ideal for the street so the GX without it
suits racing revs better one would think

Hmmm... KB10 heat riser is thermostatically controlled and heats the bottom of the intake manifold. GX uses water-heated intake manifold, also thermostatically controlled (via coolant thermostat). Which is better for performance I can't say

Isn't the GX manifold higher flowing than KB10? I think the A15E dual-outlet manifold is higher flowing than the GX.

the plot thickens A15E dual outlet manifold, never seen it DD
is there a pic of that?

As for exhaust heat vs water circulation, one would get hotter
quicker than the other and much hotter overall indeed.

As a purist or looking for good all round benefits to your kb10
eg. good economy, smooth running and factory performance
if you are using kb10 A10 or stock A12 with stock carb or slightly
upgraded induction, the kb10 manifold is a good choice but stock
manifolds flow enough for all but 90+hp capable A series.
Exhaust flow of stock mani do not restrict these little engines.

My slightly higher compression A12 with stock everything
except upgraded dizzie & kb10 A10 re-jetted carb was simply magic.
I also used my stock A10 flywheel with higher rated clutch.
This simple setup out-accelerated a similar A15 engined vb10
and he sported headers, weber 32/36, electronic ignition etc.
The smaller A series are good little rev happy engines.

Yeah, a lot of A-series owners don't know how to rev the engine ...

Anyways here is the A15E manifold. A14E is single-outlet