Zerocyde

So, the 305 tbi is gone and the carbed 355 is screaming all over town. Got a thumper cam, nice aluminum heads (don't have the numbers on me atm) and topped with a Holley 670 street avenger. Only 1 or 2 bugs left to work out, and the damned roller rockers are 1 of them.

So I got a thumper cam but not sure the lift and duration atm. I got the push rods and rockers from the guy that built the short block for me, and he's pretty professional and I don't have any reason to doubt they are the correct parts, I'm just having trouble getting them adjusted correctly.

Adjusting them while running like I did with the rockers on my old engine does NOT work. One half turn past zero lash made the car drive like GARBAGE. Half the power as normal, vibrating while accelerating, backfiring like a machine gun, just terrible.

I've since bought the tools and have begun teaching myself to adjust them with the feeler gauge, and it's been running almost perfectly since, but I need some solid tips to get it perfect.

What spacing should I use? .020? .025? .030?
Should I do the adjustment with the engine hot or would cold be okay?

After I get the rockers dealt with, I'm gonna have to figure out why I got a bit of an off idle dead zone. It's less noticeable the more gently I apply the throttle. I noticed, when I had my vacuum gauge hooked up, that when I hit the throttle, the psi drops to zero real quick before shooting up.

Any info would be much appreciated!