Ah, I have a different IDT PLL.
I found the Cypress PLL on mouser for $2.80. I'll buy it and switch it out. Messing with old cheap hardware prevents me from messing with and killing my $1k+ stuff.
I'll be back at this system tomorrow and can get hardmod info. I think all I did though was solder pins 54 and 55 together. The resulting intermediate voltage gets interpreted as a 1 by the PLL on both frequency select pins. Beware that you memory likely can't handle 444 MHz. I knocked mine down to the 266 MHz strap for 355 MHz.
Mobo datasheets here btw: http://www.s-manuals.com/notebook/dell_inspiron_8600