K-Type thermal couple connector questions

I'm currently working on an egt/wideband 02 interface module for my megasquirt MS3X ecu does anyone know of a less expensive alternative to those alumel and the chromel pins for the connetors? I'm trying to source the bulkhead connectors amd pins to connect to the module as well as pass through my firewall.

The veracity of a thermocouple is based on two known dissimilar metals reaction to temperature and the resulting temp dependant voltage (in the case of K chromel and alumel). If you start swapping to different metals midway before the amplifier you _will_ have inaccurate readings however they _may_ be stable and repeatable.

Sometimes the right answer is just a rubber grommet to pass the EGT wiring through. Another thought is to use normal thermocouple bulkhead connectors such as these:

https://www.omega.com/en-us/sensors-and-sensing-equipment/sensing-accessories/jack-panel-assemblies/mpj/p/MPJ-KI-F?&lid=92700048661953435&ds_s_kwgid=58700005357080374&ds_e_product_group_id=754817031585&ds_e_product_store_id=&ds_e_ad_type=pla&ds_s_inventory_feed_id=97700000007301780&gclid=CjwKCAjwh472BRAGEiwAvHVfGg9NjQHyUlsLvYqy2gUwYde5dEa-WRvFx1H-B4gjfOCtXhfnnMH9HBoCYmgQAvD_BwE&gclsrc=aw.ds