I am going to put in a GM847 this winter along with other parts, but my question is with the valve springs. I did a search without much luck, Should i go with Kmotion 800 or Comp 987s? Do i have to measure my install height, or can i just order them and install? What is the install height that i will need.
Along with the cam i am getting hardened pushrods and probably comp lifters. Is there anything else that i am going to need to complete the actual swap? I know tuning and all that

Thanks Scott

 

anybody?

 

I am going to use Crane 99893 since I have a set laying around nobody wants.

 

The K-800s are the way to go IMO. I ran those springs on my stock headed 97 with a GM 847, which ran 12.4 @ 111.5. Atljar runs the with his 847. I've never heard anything bad about the K-800s. Running the springs with the provided shim should give you the correct installed height (although you still want to check the installed height).