Engine Question / Lycoming G1D6 Versus G2D6

[helio.295.ak]

Can anyone give me a quick idea of what the differences between a G1D6 versus a G2D6.  I already know the manuals description of the name/character differences.  I simply don't know the detail.  Can either be used in a helio?  Will they both fit up to the same prop hub, etc?

Thanks for any feedback

[Delcourt Aviation]

The G1 engine has a splined output shaft, an SAE #20. The G2 has a  flanged output shaft. The props are not the same, and you also have to change the prop gov drive adapter.

Look at Lycoming TCDS E-275, gives a detailed discription of the different engine models in the GO-480 family.

Look at Hartzell TCDS P-907, gives a nice breakdown of What HC-B3Z20-1 means. The "20" means its a #20 spline shaft, it it had an "F", it would have be flanged.

Only the G1 engine, and splined prop are listed on the Helio 295 Type Certificate Data Sheet.
Maybe someone out there knows more.