just installed a new purple shaft cam in my 360 and it tore off a lobe with in an hour and a half.I put on the lube just like it said .then i ran the motor for an hour varying rpm . frome idle to 3000 thats how a buddie told me to do it.of course he is a chevy guy but i figured there about all the same. I did start the motor for a couple minutes and then shut it down to fix a leak before i let it run for an hour.then i changed the oil and filter ande went for a ride.by the time i got home it was ratteling.I tore it down and a lobe was worn off.it has edelbrock heads with adjustable rocker arms .io did not change the adjustment from the previous cam that was in it .it was a 520 lift cam dynamics cam.I'm thinking about installing the original stamped rocker arms back on and trying again. how long do you run the motor for break in and at what rpm? I havent been able to find this info anywhere.mabye i screwed up somewhere .the old cam was ok but didnt work to well with the 3.23 gears and was a pain to drive in trafic with a four speed.the cam i put in was a purpleshaft 474 lift 274 duration an worked real well until it tore off the lobe.thanks for any help.
I'm also not really sure how to adjust the rockers on a hyd cam.I know how to tighten or loosen the rockers but do the lifters have to be pumped up? this is the second time i had a purple shaft cam do this so i must be doing something rong.

i go for 1.5-3hrs (with an industrial fan in front of the motor) to break in any cam i put in,at a constant 3k rpm for at least half of that time. with the rule of thumb, the longer the lift/durration, the longer the break in. adjusting rockers on a hyd cam - ? i don't know either, i have only delt with rocker on cam and flat tappett.

did you put new lifters in? I run the engine at 2000 - 3000 rpm for half an hour trying to not let it idle too much. I worked at a rebuilders for 8 years and never had a prob. To set the lifters we used a system that is hard to explain but works very well. I will try to explain it now. write your firing order on a piece of paper like this

1 8 4 3
6 5 7 2
Now rotate engine so that # 1 cyl is on overlap, ( exh just closing, int just opening) now you can set #6. Then rotate till #8 is on overlap and set #5. Rotate till 4 is on overlap and set #7 rotate till # 3 is on overlap and set #2. Now set # 6 on overlap and set #1 and go through the other 3 the same way. To set rockers we just rotate the push rod thill there is drag ( 0 lash ) then 1 full turn down. Sorry so long but this is how we did it and never had a prob.