[2.7RACER]

The 2.7's have a poor reputation because when new, they were low hp compared to previous models, as well as overheating issues with the 5 blade fan, the thermal reactors and worse the pulled head studs at relatively low miles.
The 2.7's that have survived usually have time certs installed after an early tear down.
The 5 blade fans and the thermal reactors are typically scraped.
At 160/165hp they are slower than many cars built before and after.
That said, your '77 has survived, and you are enjoying the 911 experience for less dough than most.
If you live in a non-smog area, you can make the motor more potent and give the early and later models a surprise.
At 54,000 miles I would carefully watch the head studs if they haven't been reworked.
My '76 has spent the last ten years primarily as a race/AX car.
So most of the last years, it has spent it's life at 4,000 to 6,500 rpm, without any failures.
I have installed go fast parts successfully and picked up alot of performance.
Would I have bought a 2.7 knowing it's reputation? Probably not.
Is it fun beating 3.0's and 3.2's? You bet.