Just had this discussion on the other Classicopels list. Connecting rod bolts are a good idea. At least new stock bolts, but ARP does manufacture them for the CIH engine. No part number, so you'll have to call and ask for technical help. Worth noting is the bolts require .0055" to .006" of stretch for correct fitment. Based on running a tap through the rod first, and oiling with 10W-30 oil, I've found that in order to get this amount of stretch, the first torquing wil be "about" 49 ft lbs. Second torquing will be about 46 ft lbs, and third through eighth torquing should be about 43 ft lbs. I discard the bolts after eight fitments (not from dry fitting, but rather tear-downs after operation of the engine)
The first torquing basically "seats" the threads and the area under the head of the bolts, hence the high torque value. All these numbers are higher than stock (36 ft lbs), so the rod will have to be reconditioned after fitting new bolts, or the rod cap will be out-of-round.
Regarding head studs and main studs: Not necessary. Stock Opel bolts with correct torque values will handle 220 hp fine. IF you are running a crazy turbo or nitrous oxide, or rpms above 9000 regularly, then studding the mains is a good idea. I *believe* the studs ARP supplied to me in the past are 2300 Ford, but I may be wrong. As it was, I had to shorten the front 4 studs for oil pan and timing cover clearance.
Head studs: Do you really want to try to fit washers and nuts under the camshaft area? I had custom head bolts made at one time, they were 12-point heads. Still had to remove the cam to remove the head bolts....pain in the ass. They would not clear the cam shank. I again would not recommend this for a street engine, way overkill. Oh, and about $12 a bolt....ouch.
Copper head gaskets: I have some left over from a batch I had made. They're .032" thick I recall, and are sized for "mega-bores"(Used for making a 2.2 into a 2.3 or a 2.4 into a 2.5 by boring .080"). There's a few problems on the Opel. One, the oil feed to the head is pressurized, so the oil hole in the gasket must be embossed so there's a crush fit under torque. Also, the front timing cover are must be sealed separately. Also, the head gasket must be annealed or it will be too hard and will NOT seal. Easily done in a home oven when the wife is not home! I also recommend aluminum o-ring wire, I've found it is far more ductile than copper wire, and hasn't leaked on me yet. Copper has leaked. Lastly, your best friend for a copper head gasket will be Permatex Copper Spray sealer. Without it, there's no way to keep coolant from leaking from between the head and block. Let me know if you go for this option, I have complete detailed instructions for this installation, step-by-step.
Just FYI, the copper gasket is overkill as well. I only use it on boosted engines or because of the high cost of aftermarket large-bore gaskets. Felpro gaskets work fine on GT-4 racing engines(195 hp), and these things are pretty tweaked.
Solid lifters are not available in the US. They come from Europe only. Hydraulics are still available here, from GM, or TRW, or Sealed Power names. For cams, blanks are getting harder to find, regardless of what some people have told me. But regrinds can be done by nearly anyone. Isky still sells Opel cams (old profile technology though), Norris Cams, and my old supplier, Cam Techniques. They all have Opel experience.
I love the F306 cam profile from Cam Techniques, it makes great power and is still very driveable. .459" lift, 246 @ .050" duration. Very nice with 108 lobe separation on the street, or 106 degrees for hillclimbing or solo, or circle track. Roger Wilson has this in his 2.2 GT, damn thing pulls 7500 in 4th gear with a single Weber!
Bob "I really need to find a new hobby" Legere