Sounds like different issues. The motor overheating could be related to several possibilities; coolant mixture is incorrect (not at recommended 50/50 water and anti-freeze), faulty thermostat, faulty / clogged radiator hoses, faulty water pump, clogged / restricted cooling passages in the engine, fan belt stretched or slipping.

The lack of power steering could be related to a low steering fluid level, for example. The sluggish shifting may be related to low transmission fluid level - check these two conditions; for the steering system and transmission - as the first steps.

As next steps - have the stored fault codes or check engine light scanned - for free - at any local auto parts store; Advance Auto, Auto Zone, NAPA. Then, post a reply as 'add answer' with any of the specific codes for more assistance.

Ive been learning that new computers have to be flashed at the dealership.If you did the install yourself I suppose that could be the problem.

I need to know the story from the beginning. Why did you replace the computer? What was wrong with the car that led to diagnose and replace a computer?So, your description of no start means that the starter does not function? You turn the key and there is no starter cranking sound? And at the same time none of the instrument panel lights are even illuminating at all for even a few seconds when the key is switched on?

If you have good spark everywhere and the fuel pressure specs are good, check for an fuel injector pulse.
Can you check for applicable trouble codes? To check codes, yourself, at the least, you need an obd2 code reader. Your local autostore should have one.

Setting valve timing is a very tedious and precise procedure that has no margin of error. If you plug in a code reader I suspect that if your valve timing is off you will have a camshaft or crankshaft position sensor code. Has to come apart and confirm / reset valve timing using a step by step procedure in a manual.

Check the many on-line auto parts sources, such as; www.autopartswarehouse, or www.rockauto.com for the replacement parts - and to compare the applications and parts listings for the model years in question.

Exactly which type of parts you are looking for replacing in your Pontiac car? If it is auto parts it may be difficult without some new modification in old model engine area.
You should check with some expert to make some advice about your swapping, as like I do for my engine swap and get my swapping doubt clear by "hiperformer" blog pages.
You can find number of blogs and article pages where you can find some help on your swap problem.

As such there is no big difference between the two models; I don’t think there would be any difficulty in swapping parts from a 96 to a 98 or vice versa. There could be a very minor difference in both models and they should interchange without any problem. I think http://www.automotix.net/usedautoparts.html here you can solve this problem, I hope.

Test the idle air control valve by using this

Pin Wire Color Circuit No. Function

A. LT GRN/BLK 444 IAC Coil B Low

B. LT GRN/WHT 1749 IAC Coil B High

C. LT BLU/BLK 1748 IAC Coil A Low

D. LT BLU/WHT 1747 IAC Coil A High

3.1L & 3.4L IAC Valve Connector Pinout
http://www.autozone.com/.../...rGuideContent.jsp

If the readings are OK, then the powertrain control module ( PCM ) may involve. Some local auto parts have the fixture to test the PCM.

Removal

Disconnect negative battery cable.
Drain cooling system.
Remove air cleaner (if necessary).
Loosen water pump pulley bolts.
Remove serpentine drive belt.
Remove water pump pulley bolts and pulley.
Note position of locator tab on top of water pump for installation
reference. Remove bolts, water pump and gasket.

Installation

Apply thread sealant to water pump bolts.
Install the water pump and new gasket. Ensure the locator tab on top of the water pump housing
is positioned vertically. Tighten bolts to specification. 89 inch-lbs.
To complete installation, reverse removal procedure.
Fill cooling system with recommended 50 / 50 mixture of anti-freeze and water.

The PS pump is held in place by three 13mm bolts. Turn the pump pulley to align the holes in the pulley to the bolts behind it and use a 3 in. extension on a short 13mm socket. Then remove all the bolts. You do not have to completely remove the pump, just move it up enough to access the water pump bolt.