Leaky 727

Hello FABO - I have installed a rebuilt 727 in my 66 Barracuda. Mounted to a 318. When I removed my 904 it never had any issues with leaking at the dipstick tube. I am now having leaks occur at the dipstick and I cannot seem to prevent the leaks. I've tried RTV red, and it did not work.

Does anyone have any recommendations or ideas on how I can prevent a leak at the dipstick. And unfortunately like the 904 there is no bolt hold to fasten the dipstick to the transmission.

Thanks!!
My 727 dipstick tubed leaked, I pulled it out and changed the O-Ring, hasn’t leaked since :)