No link pipes, they are not Motad, as Jules-C says my guess would be Sandybikes or old style Blackwidow when previously sold as one piece, as these have clearly be designed to fit the original endcan/linkpipe to original downpipes. They also might be Lextek as they look the same as.
https://www.lextekproducts.com/DWNPP043G
https://www.lextekproducts.com/DWNPP043G