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I've had a bit of a look around on here and am still keen to know a couple of things about converting my L series to an EJ20 turbo. I'm planning on doing all of the work myself and need to sort out a few details so that I can work out a budget for the project. The engine is a 1999 model and comes with the diff from the same car.

1. Driveshaft mods- do I need custom inner CVs or can I make something with parts off the shelf? Are there pics on the forum somewhere of exactly what I need to do to get the shafts to mate up to the box?

2. Diff, what do I need to get it all to bolt up considering it's a 1999 model diff?

Thanks, Marty.

If you are using the ej gearbox then you can usually mix and match the front CV's for it work (mine is an auto, dunno if same for manual)

The rear end I had a 97 diff (bolts in exactly like the original diff), but that required custom CV shafts so I just used like 92 or something diff with original drive shafts.
Thats because I'm pretty sure the late 90s diffs had no stubs coming out of the diff.
You'll have to ask somebody else though cos I'm not 100% sure, just coming from my experience.

The biggest problem you may have is the chasis rails being in the way of your engine with a DOHC also the fact you will probably need to cut the front crossmember to get the exaust through!

tex wrote:The biggest problem you may have is the chasis rails being in the way of your engine with a DOHC also the fact you will probably need to cut the front crossmember to get the exaust through!

The quoted post is partially incorrect.
Tex - yes, the chassis rail clearance problem exists for the Brumby and other MY based vehicles.
L series, on the other hand, has no chassis rail clearance issues at all when fitting quad cam EJ engines.

There is an exhaust clearance issue with the engine crossmember. It's okay to cut and weld this, been done many times without issue, but if you can find a Turbo RX or Vortex crossmember then no other mods are required.


Front driveshaft inners - just source complete shafts, it's easier than trying to mix/match. You just need a pair suited to either an EFI L series or a turbo one. The cups need to suit 25 spline gearbox stubs, as opposed to 23 spline.

Rear diff - a 1999 one will almost definitely have female diff stub recepticals on it, which means it's really unsuitable for your car. Some people have found funky methods to "make this work" but I am not aware of any reliable ones. Best bet is to just source a rear diff with male stubs. Solong as it has male stubs a diff from any model of Subaru at all will work, solong as it's R160. The crucial thing is to match the ratio to whatever the final drive ratio of your gearbox is. Having an LSD centre is nice but not essential for the road. AWD still works prefectly fine if you leave an open rear diff in. To check the ratios of your gearbox look up the gearbox code (on a sticker near where the starter motor goes) on Google - this should be accurate assuming the gearbox is still original spec.

Thanks for the clarification I was going to post a link to the thread but couldn't remember what it was called