Bushyar15, I have rebuilt several different modders motors and was not impressed with 1/2 of them. Like Maximo has said, not very many modders change timing. I personally just do more blending and cleanup and don't mess with timing much, you can make a engine hard to tune. I also think a crank like someone pictured above maybe could make more power, but at the expense of making it hard to tune. Being a machinist I have put bypass ports in motors that don't come with them. I really like how some modded motors have many hours in them and the modder didn't even think to touch the block.
The machine I use to pinch is over $10,000 new, but pinching is not what it was made for. I have had several customers say they like mine better than others they have used. I don't pinch my motors very tight, I keep them so round they only need a coule tanks through them to go racing again. I had a customer get over 8 gallons on a motor after I pinched it.

As for what I'm trying to fix, each motor is different. The v-spec is a good example, Os changed the sleeve on the speed slightly, I've had customers update there regular v-spec to a speed crank and rod. I update the sleeve if they want me too, it really smooths out the motor, maybe not just the peak power.

Rex