Need good running T6 354 Perkins diesel/transmission for Trawler

This maybe easier than a diagnostic question on the Texas Gulf need another engine 135 HP for 44' Thompson Trawler and help most appreciated I'm recently retired 57 and have a good mechanic hoping to find one so I can take the boat out safely a lot of wind here.

 

Welcome to the Forum James.

Google brings up a lot of 6.354 engines for sale in the USA - here is a typical example :
Perkins 6.354 Complete Diesel Engine | eBay https://www.ebay.com/itm/255059452856

 

Looks like that's about a 5.8 l engine that routinely only put out about 140 horsepower in that vessel. At that rating unless you're absolutely wet to the Perkins for some reason you're probably going to be better off long-term with a 5.9 Cummins. I'm guessing a gear and a low hr or reman low hp cummins will be a much easier find and long term engine to own.