Ok first i will list the gear i want to use.

Peavey 6505+ head, Crate Stealth 100w head, 4x12 cab.

Rack gear: BBE sonic maximizer, DBX 215 eq, DBX 266 compressor, Korg DTR-2000 tuner, Furman Power conditioner.

Also I have a Tube Screamer Id like to use, and I have a few different questions.

I have no problems running all rack gear through either head with the effects loop send and return.

However, Im trying to experiment slaving the heads. I like the tone of the crate better, but I see all these people running 2 heads, tone from one power from the other. What are the pros and cons here.

Also when I do run both heads for some reason I cant get the rack gear to work.

Can anyone list a specific pattern??? eg.. Send on fx loop from crate to link all rack gear, return to peavey head. Peavey to speaker cab. thats what i did and the rack stuff wasnt doing anything. What am i doing wrong here.

Also with the tube screamer, Run it from guitar input or in the fx loop chain with rack gear??? Pros and cons?

Ok so recap. My questions: Proper way to slave the heads? Proper way to Slave heads and run all rack gear through FX loop? And where to put the Tube screamer?

Pros and cons and different workable variations please...