New England area rotary shop or engine rebuilder

I'm a mechanic on a submarine stationed in Portsmouth nh I just recently transferred here. I think it's time my motor got rebuilt. Has a slight idle issue and the power just really isn't there. I believe the omp nozzles clogged over winter. I'm running a premix right now to combat that issue. I've replaced the coils the plugs. Cleaned ssv throttle body and maf and ess and intake filter. I've rotor washed it I've sea foamed it. It is cat less and I do get a code for the downstream narrow band O2 sensor. That sensor may be bad all together I will replace it when I get back to New Hampshire. Only thing I haven't tried was new wires. The cat went bad and the coils and plugs this winter I replaced them as soon as I could. Car ran much better after that. But something still just isn't right. I've searched and poked around for weeks on here. Any clues? But the reason for this thread is is there a shop or a rebuilder in the New England area? I was going to get a rebuild in Virginia at angel motorsports for 1800 but my sea time and transfer time I just couldn't get it lined up.