i hope all goes well with the purchase of the new crown mate!!
I will also HEAVILY recommend that you go down to the CCG (canberra celica group) meeting and have a chat to Stitt. He has been playing with crowns almost as long as he's been playing with himself
By the sounds of it, you arent hugely experienced with engine conversions, so you are definitely going to want someone like Stitt and the other CCG boys to give you a hand - which is what this whole Toymods community is about!!
A 2JZ-GE engine will probably be the go, as you will really only need some custom made engine mounts and an EFI fuel system installed, on top of all the other usual things. It really is a gun motor for a straight six, probably one of the best mass produced straight sixes available - and at such a good price too!!
A 1UZ-FE will require a fair bit more work as gianttomato said - but will also provide a lot more poke and an awesome V8 sound... maybe look at this for the next crown
In any case - head down to the CCG meet. You'll be glad if you do.
Bookmarks