87 GW 360 V8 running on 6!? Pls Help!

[mattski]

My plow is only running on 6 cylinders. I replaced all plugs, cap and rotor. I am getting spark but cylinders 8 and 5 do not fire. When I disconnect wires at cap there is no effect on idling speed. I am seeing arcing when I remove the wires at the cap. I am also getting spark at the plugs when I remove and ground them.

I checked compression on #5 and it is ~ 115psi.

I am hearing some hissing from the engine.

Could leaks at the intake manifolds cause this? How involved is their replacement?

Thanks in advance,

Matt

[The Anti-Chrysler]

The intake manifold is the huge mass of cast iron your carb is mounted to. There is only one.

Your EXHAUST manifolds are on either side of the cyllinder head. There is 2. A leak from those would make noise obviously, but wouldn't cause a misfire. See my other post in your other thread.