I don't want to be a wet blanket but consider very carefully before going to an alloy driveshaft , consider the gains that can be made over the destruction if one lets go , is it worth it ?
I myself like trick stuff even when it's just for the fact of it , but these are after all street cars .
I have seen 4 alloy driveshaft failures , two of those where on Ford falcons that are stock , Ford here in Aus has had a heap of trouble with their alloy drive shafts , so much so that they quietly put 180 KPH speed limiters on all the cars fitted with alloy driveshafts .
The other two failures were on race cars and both these guys are going to continue to run alloy drive shafts due to the advantages , but they have had three made up and will only run one meeting with one unit before it goes back and is rebalanced and checked , unlimited budget you know , drive shafts are one of the few things you can't **** with , generally if things break you just fix it , not so with a driveshaft failure , first you have to get out of hospital , then you have to find another car and start again !!