Abt Zero speed?

ABT is a solid, long established company. I would reach out to them, talk to their engineers, and see what they say. Also price both systems....as that will come into play.

no it s not simplistic. The actuators have to come off and the holes have to be glassed. These gyro gales compressed air stabs are not a good design which why they never caught on. What do you suggest doing? Leaving the old forward fins? There is a reason all boats in that size range use a single pair of fins...

Bottom line on a boat that size, the best solution is To install conventional hydraulic or electric and yes.... glass the holes.

I don’t remember the exact layout of the 76. On the 80 and 84 the stabs are under the master floor, about a foot aft of the head

whatever....

They could be further aft since it s shorter. Trac will be able to confirm the best location. The biggest issue is having enough height between the hull and the floor which on the 84 prevents using the bigger actuators for zero speed

We don’t. I talked to Trac a few years ago and they said the ones we have could be converted to zero speed but may not be as efficient as with the larger actuators which may not fit under the floor. Turned out most anchorages we use the Exumas are protected enough and we don’t really need zero speed so we didn’t looked into it further

Given the location of the stabilizers, ask them how much noise they generate during zero speed (at anchor) of the electric stabilizers. If memory serves me right, when people have converted the 76'/80' Lazzara's to different stabilizers, they did away with the rear ones and utilized the location of the forward set.

The installation manual recommends installing them amidship

Pascal, yes. On the 76' Lazzara the forward fins are midship, or even aft of midship, and the rear ones are not that far forward from the stern, around 10-15' from the starn is where the aft ones are.