I am needing to order the GM 847 cam but have a few questions. I have heard that GM makes the cam and so does Crane. What are the part #'s for both and are there any differences. Where did everyone purchase this cam and how much did it cost you? I remember checking some number in GMPartsdirect.com but do not remember the GM part number. Also what are the exact specs of this cam?
Thanks

 

No difference because even the gm one you get has crane on it. Go with gm believe its like 20-40 cheapers through them. I don't have the part #, sorry, search should get it for you.

 

part # 12370847
specs: 539/558 with 1.5 ratio rockers, 234/242 duration, 112 lsa 234.95 from http://www.sdpc200.com hope that helps

 

I also need to know what valve springs and locator's you guys are using with this cam. I guess I need some springs that are good up to .600 lift. Just wondering which ones are popular with this cam. Thanks

 

You'll probably need to pull the heads because I don't think any springs that support .600+ lift sit on the stock spring seats.

 

So are we talking about major machine work to get the heads to seat a spring that will hold up to a .600 lift. What comp sriingds are guys running on the board. That seems to be a common setup. Did they have to do special machining?

 

combo motorsports cm612 springs are good to .600 lift without machine work.

 

I think the comp cams behive springs will work without mods to head seat.