i just bought my 99 SLE a little over a month ago, and the 1st thing i checked was to see if the LIM gaskit was leaking and it wasn't, now, 3000 miles later and warenty expired, and after i started reading about all the faliures, it starts to leak, its not that big a deal cause i can do it in under 3 hrs, but thanks to the bc i now know how to do it in a way that should prevent it from happening again (knock on wood)...let me just get this straight...APN UIM, alluminum framed GM gaskits, and prestone dex-comparable coolant, a few busted knuckles, and a few hours in a 10 degrees above 0 garage

You got it...from a high level. It'* not too tough, but have a Chiltons in hand to reference torque specs, etc.

Also, don't underestimate the amount of time it takes to complete the job. Cleanliness is VERY important. I've done the job 3 times on my 99 and it still takes me about 5 hours. I really take my time. You're better off taking your time doing it right, than rushing only to find out that you have to tear back into it.

I'm moving this to 92-99 for better exposure.

i got all the torque specs from alldata...3 hrs is what it took me on my 94 with a series one...

Just remember that the torque spec for the series II with the composite intake is only 89 inch pounds.

I take it that you've read the TECHINFO article #38 already?

Jason, because your car is a '99, the stovepipe that comes with the APN kit will not fit into your lower Intake manifold stovepipe bore. If you use your stock GM pipe, you will end up with an insulating gap between the hot stovepipe and the heat shield in the plastic upper of about .065". This is not a problem, but you can make it a lot better. If you have a machine shop nearby or know someone with a lathe, take the APN pipe and turn the base down to exactly .625". Add a little chamfer at the base to help get started in the hole. Then you will have a nice .125" gap between the hot pipe and the heat shield. If you have to go the machine shop route and they want more than $20 for the work, PM me. Don't forget to buy a new set of elbows for your tensioner assembly (from the Dorman Help line.) Also, some blue loctite for the manifold bolts, and some brake parts cleaner to clean the gasket sealing surfaces after they have been scraped. This is a good time to install a drilled thermostat, if you haven't already. Remember to refill coolant at the thermostat opening as described in Techinfo article 100.

is 180 degree thermostat is good for a cold climate, or should i wait till spring...and are felpro vale cover gaskits good, or should i use something else...thanks for all the info

Some people from your area prefer to wait until spring to install the 180* 'stat, but it'* your choice.

And as far as I am aware, the Felpro valve cover gaskets are fine. That'* what I have.

I like to run a 195 for the winter and a 180 for the summer, both drilled. I like to be as warm as possible in the winter - especially this winter

mine runs below 200 now, i'm gonna hook up a scanner two find out exactly what it runs....and what eactly do you mean by a drilled thermostat

A small hole (3/32") or two small holes (1/16") are drilled through the flange of the thermostat, so that air and a tiny amount of coolant can pass from the engine into the top radiator hose. This is done to help rid the engine of air that tends to become trapped in the engine causing problems. It is important that coolant, not air, fill the highest passages in the L36 engine, those that cool the plastic around the EGR bore and deliver coolant to the throttle body to prevent throttle plate icing. Thermostats used to come with bleed holes, but for some reason, (?) ours no longer do.