probably similar to 96-97 LT1, if i had to guess... know off-hand if they used the 68332 or 6811 processor in them? the 98 vortec is a 68332 based unit.

the 93-95 3100/3.4(RWD) PCM is essentially...

that would be Dimented24x7's work, i believe.... i don't know about similar to the LT1 though....