The pipes are totally fabricated to "fit" where they had to go.It had to meet 2 requirements,fit under the flat hood and not sacrifice the A/C compressor. Just used a variety of elbows and bends,a sawsall and welder.I wanted to increase the tube size right out of the compressor, but I had to clear the upper radiator hose,so it stayed 2 1/2" for a short run. This was the best compromise compared to running the tube down low and across. http://i355.photobucket.com/albums/r461/FriedDonuts/P1000750.jpg This is the crossover pipe. It runs from the driver side,which has what is essentially a copy of a high perf. factory manifold,to the log on the pass. side.