what level of psion do you think the Kigrid would be at? the original text did not specify, hence the ? in the space of its psion level.
If you show me the original monster, maybe I could answer the question. Sadly, even when a manifester level was given it 2e, it often didn't match. The monster might have the wrong MTHAC0 and an unusual number of power points, for instance. There are four things to look at: Hit Dice, MTHAC0, manifester level (if given) and # of PSPs. The # of PSPs gets the lowest priority, however, since
so many 2e monsters got it wrong.
Edit: found it.
Kigrid FREQUENCY: Rare (common in Illithid areas) NO. APPEARING: 1-3 ARMOR CLASS: 3 MOVE: 12"/15" HIT DICE: 9 +27 % IN LAIR: 20% TREASURE TYPE: C NO. OF ATTACKS: 2 claws and 1 bite DAMAGE/ATTACK: 2-8/2-8/2-16 SPECIAL ATTACKS: Poisonous bite, psionics, rear claws, for 2-12/2-12 SPECIAL DEFENSES: Surprised only on a 1 in 10, psionics MAGIC RESISTANCE: 35% INTELLIGENCE: Very ALIGNMENT: Chaotic evil SIZE: M (5' long) PSIONIC ABILITY: 90 +2d20 Attack/Defense Modes: A,E/F,G,H Kigrids may be found singly or in small groups. They are always hungry and will attack and eat any vulnerable creature. A kigrid is a stocky, four-legged creature with a short tail, powerfully built legs, a short neck, and broad head. It has sharp claws, and there are four tough, spiky tentacles around the broad, beaked mouth. The skin is black and the eyes a dull red. These beasts are cunning and malicious, and generally unreliable. In combat, a kigrid will strike with claws and teeth. If the forepaws both score hits, the rear claws may be used for additional attacks. If the beak hits the opponent, a saving throw vs. poison is necessary. A failed saving throw means the poison causes swelling and pain that lasts for 2-5 rounds (penalty of -2 to armor class, saving throws, and rolls to hit). Kigrids have the psionic disciplines of ESP, body equilibrium, levitation, and invisibility. They are perfect mimics and often use sounds to deceive prey. Their tentacles allow them a limited ability to manipulate objects, and they may rig simple traps. Kigrids generally avoid one another unless they are closely related; the more powerful individuals generally regard the less powerful as food. They reproduce in the same manner as cessirids and embracs. On occasion, large kigrids are used by Illithids as beasts of burden; how this is accomplished without constant supervision is unknown.
Was this a 1e monster? I'd say 9th-level manifesting, but you may want to reduce that slightly (mind flayers used to have 10th-level manifesting, and the Kigrid isn't that powerful).
as i see it, these (for the illithidae) need a "spell-like ability" analogue:
body equilibrium
domination
empathy
mind blank
Use the same system as the Monster Manual II, which also has a workable way around combat modes if you don't use the PsiH

Mind Blank and Domination are spells.
also, these 1st-edition powers need translation into both 3E psionics, and 3E "spell-like ability" psionics:
dimension walk
hypnosis
Dimension Walk could be a pseudo-spell-like ability, like the intellect devourer's body thief

or it could be supernatural, like the temporal filcher's time shifting abilities.
Hypnosis - there's a spell very similar to that in the 3e Players' Handbook. You are allowed to say use the spell as a psionic power, just not too often
As an aside, you are also allowed to drop powers that a monster may have had in 2e, especially if they were useless or broken. If a power is not mentioned in a 2e monster's combat section, and the power can't be used for role-playing purposes, then the power should be dropped.
also, how do the attack/defense modes work if psionics are used as "spell-like abilities"? do they work at all, or are they just dropped off if the PSiHB is not used in your game?
If you don't use the PsiH, then you should ignore all combat modes except for Mind Blast.
Even if you use the PsiH, no one uses them. The Mind's Eye is coming to the rescue in February, however, and so is the author of the Psionics Handbook - he is releasing a product called "Mindscapes" that you may find interesting, at
www.montecook.com - also in February.