I have a new set of new BBC OE style cast iron Osco manifolds and risers with less than 40 min. of run time. 100% complete with all new riser gaskets and hardware. These were installed on my 502 when I did my top end this last summer only to have a shop install a cracked head and blew the motor. This exhaust literally has less that 40 min. of time on them. PM me for details