I get all that, i wasn't making a comment on your subject, just what grumpy suggested that 3.9 is a better ratio to use with the t56 just after i suggested 3.7 in the combination of components i would recommend....
On your subject, at the end of the day the tailsgaft in an lh with a ls and t56 is quiet short lessening the issues of which you speak !
And you really don't want to go that fast in a torana lol....220Kmph feels like 350Kmph compared to a modern-ish car.....