Hi all, Last weekend I purchased a 93 Z28 with 150k miles for $2000. I knew BEFORE hand that the car had problems overheating and was getting water in the oil. I am pretty mechanically inclined, so I decided to make the purchase and pull the heads and take a look. I am pretty familar with earlier model 350s, but this LT1 is different in many ways. Here are my questions:

1) Could the water pump be a potential source for the problem. This is the first water pump that i have had that was gear driven off the cam. If it were to fail internally, could water find its way into the oil?

2) Are there any good additives that can help get rid of the residual water in the block once i get it put back together? Im planning on changing it a couple times after a couple hundred miles each time, but would like to use a product to help. Im going to clean as many parts by hand that I can while i have it apart, but know i cant get it all by myself.

3) Do these cars have a reputation for blowing head gaskets or cracking or warping heads? I dont mind if the problem comes from the heads or head gaskets. Im concerned about the block....I REALLY DO NOT want to pull the motor. What is the likelyhood that the block is damaged?

4) Finally, if i replace/upgrade the top half of the motor, do i need to worry about blowing out the bottom end? I would like to get the most out of the motor while i have it torn this much apart? Cold air intake, port/polished heads and intake, upgraded ignition and injectors, headers, and custom PCM are the mods im considering. Is this too much for the lower half considering it has 150k miles?

Thanks for all the advise!!

 

1
no, the water side of the pump is seperated from the engine oil by 2 seals and the outside air

2
not really, flush the oil out, and change it a few times after repaip, and hope for the best

3
head gaskets are common, especially if it was overheated, cracked blocks are uncommon, make sure you have a good waterpump, radiator and working fans, so you don't do it again

4
some have good luck, some don't, I say if the block is fine, go for it, if nothing else, you will have a good top end and will just need a short block