Quote Originally Posted by Mercguy View Post
No such thing as a stupid question, only stupid answers.

I think the guys over in the US have done the adapter, but not for a tremec. I believe it's either the 4L60/80e autos.
they are different lengths iirc.

an LS swap is an 'obvious' candidate due to availability and used wrecker motor prices, but in reality the cost of an LS isn't as cheap as many would have you believe, once you 'fix' all the LS known issues.

so an LS swap would still equate to roughly the same cost as a 3.5/3.9/4.4 overhaul / replacement.

Then you have the electronics, the transmission control and the adapter to think about, then the engineers certificate / mod plate etc.

Sometimes, it is best to find a reputable workshop who has performed this exact conversion and has good references and you can speak to the owner of the conversion / look at the fab work.

Having done more than a few conversions in the past, I can dispel any myth about the 'cost' which is to say you are not ever going to see a return on your investment if you go the 'mod' path.

So in that instance, I would recommend a 4bd1t, LRA chassis rail plates, a good built LR manual and LT230TC with an atb centre or at the very least hardened crosspin.

Yep, diesel, noisy, slow etc etc ad infinitum. But it is compatible with the chassis, TC, diffs and won't hurt from an engineering certification standpoint, because it is a 'known'.

No, it's not a v8, but it has more Nm and arguably a lot better fuel consumption. Therein lies the only avenue by which you could hope to recover any capital outlay.


It's pretty darn hard to make a decision when the v8 sound is usually the reason for buying in the first instance.
but when the difference in fuel consumption between a 3.9 v8 and a 3.9 diesel inline 4 is in the order of 10.0L/100km there is a definite logic.

and just so you know, anything goes wrong with a diesel, your overhaul / rebuild expenses will make you go pale.

The bosch IP for one of my OM606's was rebuilt in Perth before I bought the motor, it was still in it's box, with a receipt for $2800.

I only ever recommend people undertake a conversion after they have thoroughly researched the relative merits and remain satisfied it is feasible / financially viable
ROVER LT230 TRANSFER CASE - 4L80E

One of my best friends has done numerous LS conversions into all sorts of vehicles, from VN commodores to E24 635CSI BMWs and many in between. He has tuned standard GM ECUs with EFI Live and was able to get his VU SS with a standard LS1 and 4L80E to return close to a 30% increase in combined fuel economy through tuning alone. He was also a distributor for Marks Adaptors and could get me the kit at cost and with the ability to flash and tune ECUs, then post them to me so I was able to plug them in and be on my way, this was why I wish I went to a LS. It also helped that my Mum lives in America and I could get any and all aftermarket LS upgrades from her for a lot less than you would pay for those parts in Australia.

In my opinion, a Classic has to be a V8, which is why I would spend my money on keeping mine a V8 over making it a reliable, noisy, slow, economical diesel 4 cylinder. I did have 24 spline diffs to use with the done up 3.9 but Patrol diffs were always the goal. One of my Classics will get a LS swap in the future, I just haven't decided which one.