ya some say in pan some say in hot out line.
i got it cover bothways in my buildup.
1 in pan AND in hot out line in filter. then toggle switch to swap signal to the gauge when i want or need to see temp in line. primary will be pan temp.
i say pan temp is average. but if heavy workin i wana see temp in hot line to see if we are on the verge of melt down before its super cooled in a big cooler.
i will also be running this
http://www.summitracing.com/parts/DER-13011/ but i will swap out the nipple fittings for 5/16 dubble flare adaptors for hardline.