While I am not going to bother with it for this first AH engine rebuild, there is a later fan shroud tin development that Murbella has that did not exist on the 1974 and earlier fan shrouds.
In dealing with the differences introduced in 1975 with the L-Jetronic Fuel-Injected engines, the fan should was significantly modified in a few most obvious if you remove it from the vehicle.
There is a ring of metal at the air intake called a Venturi Ring that improves the speed of air being sucked in by the fan. (See Venturi Effect.) I can feel it on Murbella but since I have yet to drop her engine I haven’t actually seen the ring. With the purchase of that extra AJ fuel-injected engine, I got a backup FI fan shroud and was finally able to see how it looks compared to the 74 and earlier fan shrouds (Note the different location of the charcoal canister connection as well.)
I may install one on the higher-performance engine I hope to build in the next few years. I feel like I should support these small VW aftermarket vendors when I can as well, especially those producing parts that are not generally available.
Hopefully I’ll find a decent set of full tins for the AR engine. I really don’t want to spend too much money to complete that engine to get the 74 Super running again. I don’t want to use any of the pieces I currently have, though I suppose I could try and clean up the junkier ones for use on the engine. I don’t expect to get much out of that vehicle when it finally goes up for sale so I don’t want to sink any more dollars than I have to into it. I won’t know the condition of the 72’s current AE engine and tins until I do the engine swap sometime in early summer.