i just did a swap and now my motor's idle is roaring up and down, sometimes when i move around the vacum hoses, its fine, but the hoses are in the wrong position...anybody have a solution???

 

Is the throttle cable too tight?

Have you tried the idle adjust screw?

If you have a vac leak it will do that.

I tried to increase my idle for the initial 30 min high idle break in by opening up the brake booster vac line. It did exactly what you are talking about, high then low over and over.

 

Also,

open air bleed bolt on thermo housing when filling radiator. I have heard that air trapped in system can cause ilde problems cause of fast idle thermo valve on TB.