borrow some manifold vacuum

like_A_pike said

moper your absolutely right and I am also going to install a shroud and go back to a factory fan. However, since the point of ported vacuum is to actually make the motor run hotter on purpose, and I'm chasing a smoother idle anyway, I thought I'd give this a go too.

After 67Dart273 comment, I visited the holley site and that hose isn't in their manual. So I took it off, blocked both ends, and went for a ride. The motor seemed to run a little smoother. I think that manifold port just became available!

Click to expand...

Sorry, but you're mistaken. Ported vacuum is to advance the timing in relation to engine load (throttle opening). It has nothing to do with temperature expectations. If a cooling system is properly functioning, a change of 20-30° in timing at idle will not raise the indicated temperature of the engine at any speed. Manufacturers have done both ported and manifold vacuum setups when carburetors were OEM. But that had noting to do with temperature. If removing the vacuum advance hose from the ported helped the idle quality and overall smoothness, install the fan and shroud, and try setting up the rest of the ignition curve properly. You don't use the vacuum advance at full throttle, but the best way for a street driven carbureted engine to run is with the vacuum advance connected and the timing curve properly set. That is until such a point where the engine is beyond the ability to run with one, which is fairly rare.