I wouldn't use the 091 for a drag car. Although I have no personal experience on this, but its been said you can't speed shift an 091 with the stock nosecone. The mechanism in there is real goofy compared to a beetle trans. That's why Berg developed their Bus intermediate housing, so you could use all Beetle shift rods. It uses a stock Bug nosecone and hockey stick. Its too bad Berg was too stupid to recognise the superiority of the 091 'box, cause his intermediate housing only works on 72-75 002 Bus 'boxes, aka pyramid or 5 rib. This is what Mike Lawless put in his Ghia. Don't believe the article in hotVWs last spring, he didn't use an 091 like it says.
And Geoff's right, side shift would be a huge PITA for no benefit (unless you were going to use a Vanagon 5 speed)