I have a cracked block on my 1999 camaro with the 3.8 I found a 1997 3.8 camaro motor that I could buy but I've heard the manifolds need to be changed and the intake off the 1999 but is the motor the same or will I need a new wiring harness or other things

 

All you have to do since it is the same v6 engine swap is to change over all the parts and wiring to the motor.

 

You are posting in the 3rd gen section, you have a 4th generation. If you check out the V6 area in the 4th gen area. You have a lot of option. I put a 2002 3800 in my 96, click on the link in my sig. Project 96 I think I show a side by side pic and I mention the manifolds. You also have the option of getting a much newer 3800 out of a front wheel drive car. They tend to be a lot cheaper and you can find low miles ones pretty easy.