Non-diy_efi, dyno help

[xxalexx at ix.netcom.com]

> Does the IM 240 dyno use a single roller?
> If so, how do they smog the AWD vehicles?  My explorers manual states that
> for emissions checks, if it must be run on a dyno, a 4wd dyno is required.
What I mean by 2 roll dyno is 2 rollers for rear wheel.
I am not recall how the IM240 will handle this.
I have disconnected drive shaft or raised front end.
Also of interest to differential thread, I have engaged some AWD
vehicles(Galanda? Wagon and Alfa 164) on the dyno at around 50mph.  
Alot of screeching.
Alex