Original Gauges... removed or not

[Alainb]

Hi all,
I will do an avionic upgrade on my 1977 FTB337G. I decided to install 2 x GI 275 EIS , 2 GI 275, Transponder Garmin 345, GTN 650 an AP Stec 55x and the BOM from Evil aviation.
My questions :
I'd like to keep the old engine gauges and instruments. In order to have redundancy.
Can the Garmin 275 EIS probes also be used for the old original gauges?
Is that a good idea to keep the old gauges ?
Thank you for your valuable advices.
Alain