I finally got some time this weekend to work on putting the new hardware on the heads for my Challenge car's 350, but encountered something that I need some help with...
I was able to get some GMPP 1.6 full-roller self-aligning rocker arms for a steal and am planning on using them on the heads with the upgraded springs (the Vortec heads have been machined to handle the higher lift). However- I'm not certain which 'side' of the rocker the slides over the retaining stud goes down and which goes up. One 'side' is flat, and the other not.This is a bit hard to explain verbally, so I put up pictures of it in the different positions:
'Flat' side up: 
Non-flat side up: 
I can see arguments for having the flat side on the bottom and resting on the head casting where the stud meets it, and I can see arguments for it being on the top with the retaining nut (or whatever the special retainers for these arms are called...) tightened up against it. Which should it be? Thanks!
Flat side is for the polylock nut. So, the rounded end goes toward the head.
I'm not a canoe, But those rocker arms were recalled the rollers come apart and spray needle bearings down the engine. I lurk here and don't post but registered to warn you. call your local dealer and give him the number from the rocker arm.
dsxs11 wrote:
I'm not a canoe, But those rocker arms were recalled the rollers come apart and spray needle bearings down the engine. I lurk here and don't post but registered to warn you. call your local dealer and give him the number from the rocker arm.
Thanks for the heads-up. I researched it a bit, and it seems the recall was back in the mid-90s for the early LT4 engines. These came from a newer Hot Cam set and not out of a car, so presumably would have been made post-recall. But, I'll do a bit more digging when I get home and have the rockers in front of me.
They will gall, hang the valve open, break the head off the valve and destroy the engine when you put the flat side down.
Streetwiseguy wrote:
They will gall, hang the valve open, break the head off the valve and destroy the engine when you put the flat side down.
That sounds entirely too much like the voice of bad experiences... so, another vote for the flat side up toward the polylock... 
dsxs11 wrote:
I'm not a canoe, But those rocker arms were recalled the rollers come apart and spray needle bearings down the engine. I lurk here and don't post but registered to warn you. call your local dealer and give him the number from the rocker arm.
i put about 20,000 miles on a set of those rocker arms with the HOT cam in my Nova between 2000 and 2004.. the only issue i had with them wasn't the fault of the rocker arms- i forgot to snug down the set screw on the #1 exhaust rocker after i swapped in thinner head gaskets, which led to the pushrod popping out, which led to said pushrod beating the crap out of that rocker arm and bending itself into a nice lightning bolt shape, which also took out the pushrod on the intake valve.. all of this happened about 500 miles after i got the car back together as i was driving home from work one night.. i heard a "tap tap tap", which went away, and i drove it 6 miles home down a cylinder but otherwise running fine.. this is what it looked like when i got the intake off about a half hour after getting home:
the damage was limited to a pair of new rockers and a pair of new pushrods.. about $120 from the local GM dealer... so, umm, yeah, the flat side goes up and make sure you get those set screws tight...
