Banks Turbo

I have a '84 F250. My dad owned it so consequently I've performed the maintenance "leg work" which has been done religiously since new.

It has 120k on it which I will estimate 80% of that was at or near max capacity, long story short it's been well used and well maintained.

Another note it won't run below 200* F on a mechanical gauge, this all after a new t-stat and radiator.

I'm tired of driving in the slow lane driving on the highway towing my Mustang on a open car trailer = a struggle to run 70 mph on flat ground.....

Would it be a mistake to add a turbo to my existing engine or should i look into a reman long block first?

If I were to check the compression, what would good numbers be?
Thanks
Jason