Have built one clevo with the ACL Race series, 351 with 302 rods.
Very nice. But admitedly, the engine has probably only done around 2,000kms as not long after it was built the owner end up in a wheel chair.
Fear not, he will be back in action with the XD this year, but with CHI's, nitrous and a nasty auto/diff combo
Few here reckon the aren't much chop so take some advice from these people. They've used them. Only thing is that some may have been harder on their gear than is led to believe.