Flow torque insert for drag 4

[Lotus 50]

I have a flow torque insert for my 26 Trophy. I don't know the part number. It slides in and out of the Trophy easily. I tried to put the inset into a new to me Drag 4 and it would be a press fit. I don't know that it would ever come out if it could be pushed in all the way

What flow torque insert should I buy for my Drag 4?

 

[ssv1761982]

I use the Merc insert for my Drag 3 with no problem. I have ran it with small shaft and fat shaft inserts.

 

[Lotus 50]

I bought a new Merc insert yesterday and pressed it in today - not sure it will ever come out. But the prop is great from idle to 84. Pulls hard everywhere, very easy to drive.