Ant
The breather tank came from Joesracing.com
Then we modified it to fit under the fender as part of the Dry Sump tank....
And yes the 1 3/8"inch is the ID for a K&N filter..... one on the dry sump tank and Two or equal to that on the motor.....
Our breather turned out to be about 2 3/4" inches and then we stopped pressuring the block..... the pressure created
oil leaks..... ugh.....
Now it seems to have slowed down to a weep...... which is all you can expect out of a FE motor....
Morris