Raylar 202 cam in 8.1
 

Thinking of running a 202 cam in my avalanche, I have already bought full roller rockers that are 1.72 ratio, I will get arp conversion studs, Springs and pushrods,

Have read that guys were breaking studs within a few thousand miles, clearance issues, Anyone have personal experience? Is the 202 too large for this setup?

No..

The 202 will sound remarkably close to stock and is oriented towards people who tow every day. Its quite safe for stock heads - I'm running the larger 203 camshaft in my daily driver with hand ported stock iron heads.

A few hiccups come into play when buying all your own valve train parts and not running the iron head spring / roller rocker kit. Like you said, you have to purchase ARP studs, poly locks, valve springs, spring rotation eliminators and low profile valve seals. This makes the geometry a kinda one-off deal, which means you'll need to check compressed clearances to make sure your springs aren't compressing into the valve guides and crushing your seals. Your rockers may need to be shimmed to achieve the right placement. We rarely ever see bent pushrods. They'll do just fine with any cam we sell.

Here's a video we made on how to correctly put the valve train together.

After you have the whole valve train together and you're just about to pat yourself on the back - another hiccup. The stock valve covers no longer fit. There are two solutions here - traditional big block valve covers with bungs welded on them so you can run your coils, or having your stock valve covers cut, raised and rewelded by a professional.

Standard BBC valve covers which have been adapted to fit the coils:
https://scontent-b-mia.xx.fbcdn.net/..._7905148_n.jpg

The best job I've seen of the custom stock valve covers by a member of another board:
http://i360.photobucket.com/albums/o...203303_271.jpg

Or, you can run stock valve covers like mine with the iron head spring kit:
http://www.raylarengineering.com/img...troker-kit.jpg

I know it sounds like sales speak, but sometimes reinventing the wheel just isn't worth it.