727 Puking fluid out the front vent

I have a 727 which is puking fluid out the vent which is especially noticeable after it has been pushed somewhat hard through the gears. (My definition of hard is 5000 RPM shift
points) I contacted my builder and he suggested plugging the front vent hole and using the rear tail housing as a vent point for the transmission. He states that the tail housing somewhere by the upper right hand side of the tail housing has a place in it (Boss) from the factory for a rear vent. I would not have one single problem blowing the system apart and drill & Tap a 3/8" NPT or 1/2" NPT hole for a vent in the tail housing. ............actually leaning on the 1/2 " port even more.....................
The front vent seems to be 1/4 to 5/16 of an inch in the front pump cover...... I am thinking at least 3/8 vent hole for better / slightly improved overall vent purposes of the transmission.
Please advise as to your thoughts or backyard problem solving fixes................ Signed looking for answers........... Teas Red