Anybody know what rpm the TBIV ignition reaches full advance? Also how much advance can you squeeze out of these units

that depends on the number on the module..if its a V8-24 then the 24 is the degrees + your base timing..if you put more base timing in then your advance will be higher..
8*+24* = 32* total..

the number will be stamped on the side..

The rpm for full advance depends on which TB IV module you have. Depending on the module, it can be anywhere between 3000rpms and 5000rpms.

Absolutely, the SC motors had different curves than the NA motors so you need to do some research on where the module came from.

Does the preset # of the module ONLY matter when setting base timing? When setting total advance timing, does the -24 or -14 matter? Just bring up the RPM's til you see it stop advancing and set it at 34 degrees?? Sound right?

It's a v8-24 unit from a 260hp 5.7L. I upgraded to vortech iron heads, performer rpm intake, 9.8:1 compression, the lt4 hot cam with roller rockers and a 650 demon carb, I was wondering how much timing this setup will want.

Yes, that will work. Total advance is more important than base timing.

The V8-24 is at full advance around 3500-3700rpms.

With 9.8 compression you dont want too much advance. It also depends on if you want to run premium fuel all the time or not.

Start at 32 degrees total advance and you can make small adjustments up from there. I doubt you will be able to run more than 36 degrees, and too much advance will cause detonation

Cool deal. I plan on running premium gas anyways but was told the vortecs don't like anymore than 34

Actually more like 30* for vortec heads.