Does anyone in Australia still make engines? I think not.
LS3 are available locally. Here is a link to one dealer.
GM19370416 - GM PERFORMANCE CRATE ENGINE LS3 6.2L 430HP SUITS VF HOLDEN
There are more. In any case, these days shipping in is not as onerous as it used to be. Get a US dealer to pack one up and hand it to a shipping agent and in a few weeks it arrives here. Pay the duties, charges, GST and it is yours.
Bookmarks