I don't know if this is the right place for this question, but I will give it a shot. I recently bought a stock 2001 Z28 from a dealership. The carfax showed the car had a clean record, so I was not worried about body damage or anything else like that. I am usually pretty good at finding things wrong these cars. The car was completely stock, down to the paper filter. After about a month of having the car, and not modding it. I started to do the free mods to it, and was very surprised to find that my block had rust on it. Well of course it had rust on it, it is an iron block. I was in denial at first, but the numbers on the heads showed they were 5.3 heads. When looking underneath at the K-member bolts you can see where they have been turned. Is there explanation why someone would do this? All the accessories are all LS1. You cannot tell the difference, unless you look at the block. I figure someone blew the motor, and swapped in a 5.3L because they are cheaper. The car is from Texas, so if anyone might know where it came from, post up. Its a black A4 Z28. Sorry for the post being so long. Is it worth modding the 5.3 with a cam, or should I save my pennies for a LS1?

 

Well. It might be a 6.0 block with 5.3 heads on it for higher CR.

 

How can I find out for sure?

 

It actually will say 6.0L on the front of the block. I dont know if it is next to or behind the timing cover though.

 

I have looked everywhere, and have not been able to find aything. I was told to look behind the alternator somewhere, but thats a lot of work. Worst case scenario, its a 5.3. What are your suggestions?

 

As far as free mods and what not? Or discovering what the motor is?

 

Actually I already went passed the free mods. I dropped in a converter and some LT's, but these will be reusable if I decide to swap motors. I want to know if its worth dropping in a cam or not.