Newer deck.. older amps
 

im looking at getting a newer deck with 5V preouts.. should i worry about hooking it up to an amp thats from like the earlier 90's.. 93 to be exact...RF punch 40 dsm... as well as a USAcoustics usa 2100.. im just thinking is there a possiblity that i could blow the inputs to the amp?

What kind of deck?
YOu can always check with the amp manufacturers or in your owners manuals they should include the input voltage abilities.