Flash chip on Mega2560?

Hi, i want to use Henning Carlsens SPIFlash Library. He recommends some flash chips that all are running on <=3.6V. Because the Arduino has its 5v-logic, i need to know how to transform the voltage on the pins used by the flash-communication/power supply. i only found an article about how to change the whole Mega-Voltage. what i want to do is change just these pins. somebody recommended a 74HC4050-chip for transformation. my question is, if somebody ever did it, because i am not sure about the signal speeds etc. is it possible to simply use some resistors between the arduino-pins and the flash? will that work, or does the signal-behaviour change in that case? any experiences?

thanks!

Can use resistors, but only at slooow SPI speeds as the signal edges won't be as clean. '4050 will keep signals in better condition and allow full 8 MHz transfer speeds.