Thread: What's this?

Both mine were suffix D and had those air filters fitted.

Unless you are doing a rivet counting rebuild, it doesn't matter which air filter setup you use.

Do you have something else to fit to it?

As per James Taylor:

From mid-1976 Range Rover engines for continental Europe and some other countries continued to have the ''detoxed" specification established earlier, but Australia introduced new ADR27A emissions regulation, on 1^st July 1976, that called for a special version of the engine.

This had a belt driven air pump, with external rails alongside the cylinder heads that injected air into the exhaust manifolds. Each carburettor had a separate air cleaner, and each air cleaner had its own temperature control valve in the intake. The carburettors themselves were fitted with automatic chokes. These engines also had an exhaust gas recirculating (EGR) valve, and an evaporative emissions control system with a charcoal canister that prevented petrol vapor from the carburettor float chambers and the fuel tank from escaping into the atmosphere.

Suffix letters alone do not identify these engines. A new system was introduced in the mid-1970s, and affected all Rover V8 engines built from mid-1976. The prefix code normally consisted of two numbers plus a letter. (the list runs from A,D,E,F,G,K). Then the Suffix number starts at: 10A and runs all the way to: 10K (which did not go into production), A,D,E,F,G and K.