Blackdog: Hey Steve. I did not even know you belonged here. Good to see your posts.
Exiled: While I cannot claim to have been using heroin in 77, I can talk about the early 80s onward and lament that is dead and gone. There is still open air dealing but it is very low key, difficult to connect, and low purity. If you want good product, take a dollar van from GW Port Authority over th ePAterson and walk. t is low count but good quality. Blmont in the Bronx also has some decent open air places but they are also low key.
Soule: No need to be jealous of America, you have the best heroin the world, SE Asian and usually untouched.
Twig: Tar can come into the 90th percentile for purity.
As for Newark and the best heroin, it is nonsense. The DEA has a piss poor system for classification. It makes 10 buys in a given area, gasses them and then averages out the purity. Fine, except there is no control over the samples as in they can be bought on the same street, even the same dealer although they claim not to. From expereince, I would offer Irvington as the best in the NE.