"special high performance" 360?

That is because Mopar didn't follow a strict set of rules that they ever published. I was told that in 72-73 even the 340's had 360 marks on the sides of the blocks. Not so! I have a 340 out of a 72 Duster that has the numbers 2780930-340-3 followed by a large 4. I bought the car from a guy that had just had his 5th child a year before. He had bought it new then got married. I bought it 81 and the motor was smoking, the drivers seat you could see the floor thru the seat. He had literally drove it into the ground. The brakes didn't even work and the batt was shot.
I put in a set of rings, bearing and timing chain and a 284 cam then put it in a 78 Volare I bought new. I beat several 350 Chibby's (Nova's and Camano’s) in a car that weighed almost 4000 lbs. It was a Volare Premier (the luxury model)'
I still remember the look on one guys face whose dad owned a gas station and they had just built him a HOT new high compression 350.
I still had the low compression 340 with hookers and a 284 crane cam and 3.23 gears.