sorry can't give you definitive answer to your question, but in my opinion then no i don't think so.
both those cpu's are am3+ with a power draw of 95watts
from the little i can find out that MCP61PM-GM motherboard has a max cpu draw of 89watts and is socket am2,
so even if the motherboard had a bios update for those am3+ cpu's to work, and the cpu's were backwards compatible with am2 socket (which i don't think they are but not 100% sure, more an intel guy myself.) then the power limitations of the motherboard alone would cause instability problems in my opinion.
http://www.tomshardw...bo-mcp61pm.html
i can't find where it says what motherboard is in that emachines pc you linked too, but it has an am3 cpu and 4 memory slots each capable of using 2Gb memory sticks giving it a max 8GB capability.
my best advice if you want to upgrade would be to upgrade both the motherboard and cpu to socket am3+ choices.
Edited by terry1966, 24 September 2014 - 04:22 PM.