I put an Auto VT V6 into my Manual VS S2 and I put the flywheel on with no dowell pins, it was just a pain in the butt to line up the holes because it only goes on one way. Dowell pins arent for strength its just to line it up. I have a Getrag with a heavy ass Dual mass flywheel and all i did was replace the TTY bolts and it runs like a dream. I didnt balance anything and I have no vibrations. Ive 'shock loaded' it pleanty of times and it hasent come into the cabin yet so im convinced that dowell pins and a balance arent needed. Oh and yes, new loom and manual PCM is needed.