crossover pipe


Is the Poston's crossover pipe a 2 1/2" or a 2 1/4" diameter pipe? Would like to maintain the stock diameter to retain low end power. Also, saw a one piece crossover on Kirban's site and on John's performance site. The crossover pipes appear to be identical in appearance (same price$) BUT, kirban's says its a 2 1/2" and John's says its a 2 1/4" pipe? What gives???
LASTLY, Which is the better way to go, One piece or two?
Thanks for replies. I do have a stock crossover but while replacing the drivers side header with an ATR unit, i noticed that the ball flange on original header was egg shaped and not round. I am assuming that the stock crossover pipe flange is probably out of wack as well. I am afraid that if i re-attach the stock crossover to new Atr header that it will in turn distort the ball flange on new header and create a leak. Is there anything i can do to correct the mis-shaped or distorted flange on the crossover prior to re-using it. Also, I am sure that the passenger side header has some distortion as well (egg shaped). What can be done to the ball/dounut flange on the header to return it back to a round shape for better sealing? :confused:
That's actually a good question. I have a ATR DS header that the ball is out of round as well and a 1 piece I ordered from Johns Perf. The postons 2 piece I had fit better, but would not seal and leaked at the joint even with a band clamp. So I prefer the 1 piece just because that's one less thing I need to either have welded or worry about the clamp leaking. I would be interested in knowing if these can be fixed because the ATR header is in great condition and only maybe a year old. I was close to ordering a set from TA, but decided to buy a 10.5" Protorque converter instead and a stock replacement header from Anyone that can repair these might be able to start a little business.
Thanks Marc87GN. I think i will probably go with John's performance one piece crossover. Do you know if the John's crossover you have is a 2 1/4" pipe? It looks a lot like the one Kirban's is selling advertised as a 2 1/2 " pipe.
Also, If anyone has any recomendations on how to restore distorted header ball flanges or crossover flanges, Please Chime-In! :confused: