Diff upgrade for 300hp?

[unstable load]

So there's a 3.9 for sale locally (I have a 'stiff' 3.5 that needs rebuilding). Is it worth it to spend the $600 he's asking to start with a 3.9? Does 400cc make that much difference in the end? I'm guessing every cc counts - I'm just trying to justify it to myself.

Does the 4.6 have the same mounts/bellhousing and can it accept the P6 sump/timing cover etc?

It sounds like you are in the US, why not hit the breakers and find a late Discovery or P38 engine and fit that, with EFI and the whole shooting match? There are guys that can modify the ECU to run as a stand alone unit, or you can go full fat and fit a ZF 4HP box and use the electrickery to full advantage. The ZF box will be a 4HP22 in 2WD guise, but the infernals can be made to fit from the electronic box if you have the right mechanic.

 

[TokyoP6B]

In the “Members Projects” there’s an archived thread at the top where a Jag diff is installed in a P6 2000 ( which has also had a Ford V8 put in! ) Very neat install

G