I’m trying to use SHIFTIN between a 16f1936 at 5V and a 3.3V MAX31855 T-type TC to digital converter.

Question: What is the most common method for communication interface of a 5V device with a 3.3V device? There are three lines between the PIC and the converter. I didn't think about the problem until I could not communicate with two MAX31655 which means I may have smoked 'em.

Select 5V from PIC needs to be 3.3V I think
CLK 5V from PIC needs to be 3.3V I think
Data 3.3V from MAX should be OK

The PIC drives the Select line from high to low enabling the converter serial output. The PIC supplies the clock and the converter drives the data line as communication is only one way from the converter to the PIC. Will a 1k ohm resistor in the CLK line create any problems? Will a 1k ohm resistor in the Select line cause any problems? The Data line is being driven by the 3.3V converter and should not have any problems, PIC should be able to read 3.3V and lose no data.
Comments please!

Wayne