Brake Master Cylinder

[SAJanesick - Bellsouth]

Chipping down the list of things to fix a binding RF caliper, the next item to change is the brake master cylinder.  AutohausAZ has one at $300+, but since the car is so old and this is something of an experiment, I opted for a cheaper rebuilt unit from RockAuto - CENTRIC Part # 13033110 - for $103.  The unit I received is apparently similar but not identical to the original.  

The rebuilt CENTRIC looks like the BMC for the standard 200 Quattro as illustrated by AutohausAZ. http://www.autohausaz.com/search/product.aspx?sid=5lqoz045vymflc45bhb1fg2p&makeid=800002@Audi&modelid=1007277@200%20QUATTRO%20TURBO&year=1991&cid=14@Brake%20%26%20Wheel%20Hub&gid=1836@Brake%20Master%20Cylinder 

The BMC for the TQ20V appears identical except it only has two ports vs. the four ports above. http://www.autohausaz.com/search/product.aspx?sid=5lqoz045vymflc45bhb1fg2p&makeid=800002@Audi&modelid=1007288@200%20QUATTRO%20TURBO&year=1991&cid=14@Brake%20%26%20Wheel%20Hub&gid=1836@Brake%20Master%20Cylinder

According to an ATE cross-reference site, the internal specs are the same in terms of bore.  Externally they appear identical save the two additional ports.

I have not fitted it yet in case I need to send it back.  

The question is has anyone used the unit for the standard 200 and capped the two additional brake line feed holes with a threaded plug and then successfully used that BMC in the TQ20V, or are there internal differences that require the original 2 port version?

If I can save $230 by altering the 4 port BMC to a 2 port, then I'll be satisfied to drive around town.  No track time intended.

Thanks,

    - Steve Janesick