Sorry i havent gotten back to you yet man, But the shop made no sense at all. This is exactly why when ever you have a highly modified or even turbo car for that matter you should at least know what the heck your doing and how to work on your own car. I understand that some people dont have the time or knowledge for it but want a fast car. In that case you should get something that comes factory turbo and is fast that wont have the problems of custom work done.
My 2 cents. Seriously man, if i was there i would be more than happy to hook up your car, build you a solid motor that you didnt have to think twice about and could beat the absolute crap out of it and not worry about a thing. Except maybe a tranny or two, haha.
Thats why i built my motor using all top notch new parts on it as far as the engine itself goes. I didnt mess around and you know what, if was 100% reliable, never had any problems, 10k miles and when i took it apart, everything looked the way it did when i put it in, clean, fresh, and wear free. This is what your motor should have proved if it was done properly man. I can tell you i wouldnt have made the mistake of putting that old tensioner in thats for sure. Even though its probably not the problem and you more than likely spun that a bearing, Again whenever you do those coated bearings like that especially coating a standard bearing, you close your gaps on the oil clearance and with no changes to the crank you will have problems.
This is why i use standard bearings or nissan sized bearings and measure the crank to make sure the tolerances are within spec. Again yours may have been but the changes to the bearings is what did it. The calico coated bearings in my opinion are not worth the extra money at all. Too many problems. When that coating starts to come off you will again start having problems.
Wish i was closer to you man, i would hook you up but sorry, all the way on the other side of the country, lol. Hope you get it all figured out. I will still give you a call later this afternoon. Still busy doing some stuff.