Pistons

Dan the man said
I've noticed that when somebody builds a 360 that they seem to always use KB-107 pistons. The ring end gaps have to set according to what kb says. Now, I don't know this as a fact or from personal experience but I have read and talk to people who have used them and they have said that kb pistons are known for breaking in the top ring area because they don't handle detonation very well. I haven't heard or read this about the speed pro hypereutectic pistons but again I don't know any of this as fact. Speed Pro pistons don't need any specific ring end gaps as they reccomended the piston ring manufacturer's gap. Also the speed pro pistons have friction coated skirts. The compression height between the two is like 0.015". I thought that I would ask the guys who build engines from anywhere from mild to race, what are the advantages of the kb pistons over the speed pro pistons? All that I've said is only from reading and talking to different people who have built engines. I'm not saying that anything that I've said is true or not. Just asking.

Hey Dan. I’ve built several 360’s using the KB-107. I have also used the SpeedPro pistons. They also need a specific ring end gap and following the KB instructions will suite any hyper piston.

If the gap isn’t enough, the rings touch and press against each other applying pressure to the piston. The top is the weak point of the piston. Enough pressure from the rings, the top will pop.

Bad ignition timing will wreck any piston.

The advantage of the Speed Pro piston is the coated sides.
At one point in time, the pistons and ring package by Speed Pro was cheaper than the KB. Price check is always the order of the day on parts and even more so since these two pistons are really nice street parts with differences being extremely small.