TR5-6 injector feed pipes were available in a variety of forms during the life of the TR5-6 and 2.5PI
Set out below is the whole picture however, whilst we can supply plastic (nylon) pipe, second hand pipe assemblies and new plastic pipes in sets, we believe Plastic Injector pipes are fundamentally unsafe compared with the Braided Stainless Steel alternative, which we there for recommend. See RTR4107

517305 Black nylon pipe originally sold by the yard, now by the metre (5 yards (metre) per car required)
517305/1 Number 1 pipe (no fittings) 30 ¼" (769mm)
517305/2 Number 2 pipe (no fittings) 31" (788mm)
517305/3 Number 3 pipe (no fittings) 30" (762mm)
517305/4 Number 4 pipe (no fittings) 29?" (740mm)
517305/5 Number 5 pipe (no fittings) 21¾" (553mm)
517305/6 Number 6 pipe (no fittings) 20¼" (515mm)

Ends
517306 Straight Nipple and Nut, 1&6 at the Metering Unit
517307 Elbow to all injectors plus 3&4 at the Metering Unit
517308 Banjo Union, 2&5 at the Metering Unit

CP cars. Pipe assemblies CR Cars
149566Number 1 UKC0351
149586Number 2 UKC0361
149576Number 3 UKC0371
149575Number 4 UKC0372
149585Number 5 UKC0362
149565Number 6 UKC0352
All these pipes are available second hand

Sets
UKC351SET is a new set of Nylon piles with ends fitted; available in Black, Blue and Red. Only available to special order as RTR4107 is a safer preferred choice.

RTR4107 is a completely new set of Teflon lined, Stainless Steel Braided Injector Pipes complete with all new fittings. As the outer sheath of these pipes is braided Stainless steel, there is significantly less chance of abraded damage and therefore high pressure fuel leakage over standard nylon pipe.