360 Magnum vs 340 mild street build - my experience

So I have a line on a 1997 360 magnum with low mileage and maintenance of oil being changed every 3,000 miles. For $300.
Into my 65 Plymouth Barracuda that has a 273 dual exhaust in already, that would be a good thing?
Automatic transmission.
And yes, I will be keeping the 273 for my kids if they want to chamois back.