Hi Guys ... after a while (that felt like forever)
So my lesson learned - never judge engine after removing one cylinder head :)
After I took down the second one o found some scratches in cylinder 6 and suspicious spot in cylinder 7 that could be a crack. So my optimism was gone and I knew I have to disassembly whole endine. I made penetration test of cylinder 7 - and it came out that it was no crack. The biggest disappointment was then I realized that the engine is already 0.040 over. The bearings of connection rods were also destroyed as well as on crankshaft.
I spent hours on net to browse 351w topics and videos, what are my possibilities. To bore it over to 4.060" is to risky, to sleeve it to expensive and to find some good block for reasonable price in europe is impossible. So I decided to just refresh the engine (hone the cylinders, re ring it and change all bearings, timing, cam, lifters and oil pump), put it together so I can finish the car. With finished hone I was able to get roundness and taper to factory specs, but my bore is up to 0,002 inch over the top limit. Anyway, no option at this time, at least the crank is 0,010 under so I can let it grind to 0,020 and balance. Im looking now for parts to order. Except piston rings and camshaft it should be no problem.
Rings - I'm not sure if I buy 0,040 over rings the gap will be not too big (my worn rings make 0,026" gap). I'm thinking to buy 0,060s and grind them to size, but I don't know if the shape of rings is already different because of bigger diameter.
Camshaft - I can't find some stock cam or some alternative in any shop (everywhere is only edelbrock performer + )