Is the 'Fighting Bro' AEG gear a straight fit in the Wells M4?

Anyone upgraded their M4 Cylinder, Piston, Cylinder head with the Fighting Bro AEG gear?

I found the cylinder to be 3mm short and the air nozzle didnt fit the best… although I think I could have gotten the wrong air nozzle.

Wells has a 69 mm cylinder, the FB is probably modeled of a V2 gear box which has 72 mm cylinder. The wells has a bigger head and smaller cylinder to get the same length of tappet plate movement needed for gel blasters in a v2 airsoft geometrics.