Ignition???
 

I have noticed lately that in the higher rpms my 98 SS starts to stumble and spit a little, not really bad. I have had 1 or 2 miss shifts. I have 63000 miles on it. I'm planing on replaceing the plugs and wires soon, thats what i figured the problem was. Could I have bent rods and how would I be able to find out??? I have also noticed a slight knocking(not very noticable) when I first crank it up. Anybody got any suggestions?

David S

Bent pushrods would be characteristic of the problem you are having. The only way to tell for sure would be to pull them out and inspect them yourself. The way to tell, is to roll them on a perfectly flat piece of glass (like a glass coffee table), or if you dont have that, take two of the pushrods and put them together, and roll them around each other, and see if there are any gaps between the two. If you see any gaps in between any of them, replace them ALL.

It could be bad plugs or a bad coil pack as well. Since you have a 98, with relatively high miles on it, I would change the plugs and possibly even the wires since those are the easiest to do. Changing the coils isn't hard either, but its expensive to just start replacing them without knowing for sure if they're bad.

Lastly, it is normal for an LS1 to have a slight tapping noise when the engine is cold.

Thanks for the help, just bought the car with 58k miles on it. I have no idea when the plugs and wires where last changed. So I'm planing on doing that sometime soon. If that doesn't solve the problem I'll pull the rods. Would it be a good idea to replace the oil pump with a ported one?

David S

The 98 oil pumps were notorious for randomly going out. If you were planning on a cam change, I would definitely recommend changing the oil pump, but if its not giving you any problems now, I would just leave it alone until you have a reason to take the front of the engine apart.