"The cost to retrofit CiES senders to a pre-74 B55 is around $3200 (plus installation). That may seem "outrageous," but it's only about 50% more than what it costs to have the eight (2 per tank * 4 tanks) senders "overhauled" – and my experience with overhauled senders is not very good. At best, the overhauled senders will perform as good as when new for a few years – which is to say they're accurate to within about +/- 5 gallons.
"Properly calibrated the CiES senders appear to be within one gallon. In a Bonanza with two 40 gallon tanks, or a post 1973 Baron, there are only four senders so that cost is cut in half.
"IIRC the last time I checked, new (1940s technology based) senders from Beech were around $1,600 each or over four times what CiES charges."
