360 converter

Thanks for all the inputs guys

See if I got this right.
In the way it is set up for the moment, with the 273/904 converter, the pilot hub is too small for the 360 engine crank. And could cause a failure if not taking care of.
And if I use a 360/904 converter it won`t fit with the -66/ 904 tranny?
Because the converter has 27 splines and the tranny got 18 splines ?
But could this be accomlished with a special buillt converter, a mix of a
1,81" pilot hub / 18 spline converter ?
Or would it cost moore than solve it with a later buillt tranny?