Doing a diy y pipe for manifolds on a 96 f 150 5.0 and need a measurement of the flange center to center or inside dimensions on the down pipes Using 2 1/2" all the way, referencing the stock y pipe is not an option, doing a mock up of the y pipe for my son and have no access to the truck at this point but want it to fit up good to the manifolds. There is no information on google on the dimensions of the stock y pipe to be found no matter how it's worded. Anybody know this measurement so I can finish up the final weld on my son's new custom y pipe and stubby exhaust set up?

 

Only way I know to do that is build the y pipe on the truck. Sorry.