To bolt the engine in you need any 1st gen. front cover and a GSL-SE oil pan. You must also address the fact that the crossmember is further back in a 12A car. That means you need to either slot the holes in the crossmember and engine bracket to account for the 20mm difference or buy the bracket from Racing Beat that is designed for putting a 13B into a 12A car.

If you're running MegaSquirt there is no issue with the OMP. You can run a 1st gen OMP or just premix.

Search for posts made by Steve84gs. He is the goto guy for the S5 swaps in 1st gens, By going MegaSquirt, you can eliminate some of the issues related to the electronic mop, ecu and limp mode that make the S5 swap a little more difficult when compared to the S4 swap.

You can eliminate the electronic mop, but you will need to pre-mix. This only works if going with a standalone ecu. You will need the SE oil pan. If premixing, either the 12A or 13B front cover will work, along with the oil pickup tube. The SE front mount bar makes install easier too.

How does it do that?

There is a slight difference between the 12A and 13B front engine mount bars. 12A can be modded, 13B is bolt in.

The 13B bracket does not allow you to bolt the 13B straight into a 12A car. The difference is in the crossmember. That is why RB make a bracket specifically for this application.

Really? I'll will have to check that out. It was my understanding the difference was in the mount that bolts to the front cover, not the cross member. I have both brackets on the shop, I'll see if I can find them for comparision. I don't have the SE cross member.

REVHEAD, you are correct. I didn't realize the crossmember was different between the 12A and 13B chassis. Thanks for pointing that out.

Yep,it is in the crossmember....but its a minor bit of work to slot the front mount bar to make it all work.Or just buy the Mazdatrix mount.
I was unaware of the difference back in the late 90's when my first (carbed) 13B went in. A little grinding and everything was fine.I did use the correct 13B right side rubber mount.I think that makes the whole, line-it-up job a little easier.

If your gonna run any 13B and ECU from 89-92,your gonna need to adress the metering oil pump.It cannot be removed from the electrical system or the ECU will go nuts,and it wont bolt up to any 1st gen front cover without mods.There are several ways you can approach this problem.Some are simple,other are complicated...but only a couple are really "correct" and would be worth recommending......

1st.....Modify the front cover to accept the MOP.
Thats what I did.It best replicates the stock S5 setup,and keeps the ECU happy while also having the MOP bolted up and plumbed to the engine in a conventional manner.The mods to the front cover involved heli-arc welding the cover,machining the pad flat and drill/tapping new holes for the S5 OMP.....cost about 175 bucks and took a week to get back.Worked great for years now.....

2nd.....Install a complete 2nd gen front X-member.
This is a project in itself,but it will make the 2nd gen engine bolt right up in a completely stock config.It will also give you the much improved 2nd gen suspension,steering and brakes....all of which are great mods on a 1st gen.Not many have attempted this job, and few(if any) have much real time experience that they've contributed to us here,in regards to how safe or complex/complete this swap is.I know it can be done,but its more or less uncharted territory(unless someone wants to speak up!)

3rd.......Run a standalone.
Fine, if you can swing the cost and tuning required.Standalones are reliable and abundant,but can cost some bucks. Also it will never be smog legal and will require re-tunes if you modify anything.One of the simplest and the best power making way to go,but there are pluses to running the stock ECU as well.

4th.....Plug in the MOP,tie it off to the side and run premix.
By far the simplest way to go,I proved it would work for the week my front cover was being made.Premix is proven to work great on rotaries and you can run syn. oil in the pan now.The MOP stays plugged in to appease the ECU,although its not actually delivering any oil.And thats the catch....without any oil running through the pump,theres no telling how long the unit will hold out.The metered oil provides lubrication to the internal parts of the MOP before its delivered to the engine.With the electricals plugged in,the metering parts of the MOP are still moving and sliding,in tune with the electrical stepper motor,which is operated by the ECU.The stepper is equivelant to the mechanical pull linkage of the older engines.

5th.....Have the stock S5 ECU reprogrammed to delete the limp mode.
Not sure if this has been done yet.Might be worth asking around.It would allow you to just delete the S5 MOP and run premix or rig up an older mechanical MOP on the front cover.

6th....Run the S5 engine with S4 controls and ECU.
Kinda a step backwards,but I also did this for a short time before getting my S5 setup all ready.The S4 uses a mechanical MOP that will bolt right up to an SE front cover.The S4 controls/ECU are dumber and more restrictive,but they will work with a S5 engine and manifolds/turbo.I dont recommend going too high with the boost in this configuration, however.

Wow! Thanks for all the good info!

And now I'm wondering about the transmissions. Can I put the tailshaft from the older transmission onto the newer one? because the shifter location is different

Also been covered a million times.Search,youll find all you need regarding the TII trans swap.

The shifter on the TII tranny can be moved forward by pulling the tailcone,cutting the selector shaft down an inch or so,then installing the 1st gen shift tower onto the TII tailcone.That will keep everything inside the TII trans stock so theres no strength issues,but the shifter will be dead center in the stock 1st gen tunnel hole.....like this.

http://img.photobucket.com/albums/v2...y/DSC01491.jpg
http://img.photobucket.com/albums/v2...y/DSC01505.jpg