Been there done it,had my 301T for 4yrs put a few $$$$ into it over that time including a new turbo,then blew a piston late 2013, engine had to be pulled, the estimates I got for a rebuild were similar to the estimates you got,It came down to money for me, buying a used Pontiac 400 motor,refreshing it a bit, a new exhaust system and the install was a few thousand cheaper,it pained me to a degree because I had a 100% stock original Y84 car but then again I`m not selling it so being original doesn`t matter anymore,If being original is crucial re-build it, the turbo cars are becoming more and more rare so if resale down the road is an issue keep that in mind,alot of guys on these forums bash the 301T call it a boat anchor etc,I was content with the way it performed over the 4yrs I had it and it would still be in the car if it didn`t have to be re-built, no your not gonna shred tires,or win races but it is a great cruising motor and not too bad on gas,like Kev said the 301 garage is a great site the guys there helped me numerous times and you can reach out and get the hard to find 301T only parts there,tough decision for sure Do what your finances allow,