head question adjustable or not?

Use a stethescope(or your ear to a long screwdriver), and try and pinpoint the ticking noise. Is an area more pronounced than another?
ALL the roller rockers I have ever seen, make some noise. They just do.
As far as being adjustable-I'm not sure what you mean.
All roller rockers are adjustable---hyd roller camshafts almost never need to have the rockers adjusted after the initial setting and adjustment. Mechanical or solid roller camshafts will need to have the rockers adjusted from time to time.

Is it possible that the ticking has always been there since the beginning? If so, it will be worth your time double-checking the initial preload on all of the rocker-arms (lifters). It is a simple process and is well documented in the Ford manual.

From past experience, not everyone has a brain when building engines. I purchased a 302 long block years ago where the engine builder put in a 292 .525 lift cam with monster springs and press in studs. After installing the motor and breaking in everything, I was about six miles down the road, when all my lifters started making a ton of noise. I pulled the valve covers off on the side of the freeway and just about every rocker arm was loose. It turned out that the high spring rate and lift on the cam had unseated most of the press in studs. Off came the heads and into the shop for screw in studs and guideplates.

BTW - I was 18 and had no clue what I was doing either LOL.

-Chuck

All roller rockers are not adjustable. The GT40P heads use the "bolt down" rockers that all the stock small block heads since 1978 use. The guy was correct that you may need longer pushrods. Slapper was also correct that the roller rockers are noisier than the stamped steel ones.

I have noticed that the roller cam pushrods have a habit of wearing to a knife edge from not spinning like the flat tappet ones do. This may be the case with your's. Or you might have a sticking or gummed up lifter. The roller rockers in my 5.0 sound like a sewing machines running in there. This happened with the Cobra ( Crane Energizer) rockers I had before I swapped heads and now with the Comp Cams roller rockers on the Canfields now. I would also look for an exhaust leak too. I would have also suggested the AIR injection tube on the rear of the heads doing it, but if I recall correctly, the GT40P's don't have AIR injection plumbing. A ticking noise is annoying but hardly something to worry over unneccessarily, I doubt your motor's not going to self destruct from it. New pushrods are cheap, so if yours have a lot of miles on them, you may want to spend the $25-30 for a new set ( Ford Racings replacements 6.25 inches long) they're easy to replace too, your just need a torque wrench and a few other hand tools.

The stock and motorsport rockers aren't adjustable, but if they weren't torqued in sequence then it's possible a rocker is slightly loose. The pedestal style should be torqued to 15ftlb, but in sequence while both exhaust & intake are closed.