FJ will bolt into an S13 with no custom mounts, I did it. Unfortunately the intake hits the hood but a hammer fixes that.
Parts list;RB20 transmission(shifter sits perfect in the hole)RB20 automatic transmission crossmember backwards(moves the transmission back)CA18 front driveshaft(KA or SR may work, I used a CA)one CA18 motor mount, one FJ20 motor mount.
You won't find one in the states but I am sure one of the larger importers could source you one. Not mine though
If I had the money I would just have Tomei ship me a crate motor, it's just $10,000 plus shipping.
http://www.tomei-p.co.jp/_2003...#fj20