My MK1 V6 has a set of pacemakers a 2 inch split system and soon to be fitted 1 muffler and hot dog for each pipe.
Question is should I also consider a cross over pipe between the two. If so where is it normally fitted? What are the pros and cons? what is the theory of the cross over pipe?
Cheers

I cant think of any "cons"......
....."pros" being :
 
1. One side takes it in turn to act as a "surge tank" for the other side in between power-pulses
2. Quieter in decibels and "drumming"
3. Stronger as x/over pipe acts as a "strut" between both sides
4. Tailshaft explosion restricter (not likely in a well maintained vehicle)
 
Normally fitted at a non-interference convenient spot anywhere soon after rear of Tranny