I have the CiES frequency senders, with matching Aerospace Logic gauges.
Working with Aerospace Logic requires patience, but in the end, the result is really spectacular.
Yesterday, at 8500 AGL, I ran both R&L Auxiliary tanks down to 0.0 gals, at 47:35 on the clock, precisely as expected... A few seconds later... Fuel pressure begins to fall, immediately switched back to left main.
Accuracy... It's a totally new experience. I have two fuel totalizers. One Shadin and one in my G4. Maybe having accurate fuel gauges is overkill... But it's an overkill that I like.
The only caveat is that my shop wasn't particularly efficient with the remove / reinstall / remove / final install / calibrate process. I have ALOT of money tied up in this. But I don't regret it, and I would do it again.
For anyone who is considering CiES fuel senders these things are awesome. They are well worth the work to install. I ran all new shielded conductor up to the back of my JPI 930. Finally I have a reliable and consistent fuel measurement in my airplane.
Wow, who would have thought accurate fuel level was possible.
If your airplane is down for an upgrade I would send your old fuel senders to CiES. This will insure that the senders are appropriately set up the first time. Beech in all their wisdom made numerous different senders inverting the bolt patterns on some etc.
CiES senders can work by resistance, voltage or frequency. I would chose at a minimum voltage if you can, Frequency is even better.
Scott @ CiES knows his stuff.
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.