Originally Posted by
PerfInit
Not so fast.. You should carefully research Part 61, Pre-requisites for Practical Tests, before dismissing the change to aircraft make/mode has no other requirments. Some practical tests require a specific minimum number of hours in make/model before being recommended for the test. Your example is too vague to really answer. You may be OK, but I'd rather you and your CFI research and make certain you don't overlook a requirement..
There is nothing in the FAR's that prevent the OP moving from the Piper to Cessna. Just make sure you know how to utilize all the nav equipment in the airplane you choose.