You could use the engine longitudinally like a dwarf/legends car, but in the middle. Check out the ads on www.dwarfcarracing.com
for driveshaft adapters.
Obviously, this would be kind of long, but if the drivers feet were in front of the front axle, rather than behind, it might work in a relatively short WB. It would also avoid having the header right behind your seat
I am unaware of any right angle adapter to use your engine transversely with a connection to the yoke on the rear end
A V4 engine might be shorter and better suited to a longitudinal set up than an inline. V Max's appear both powerful and torquey which would be good for autocross.
I am also building an A Mod I am using a GM carrier with chain drive and VW fox axles. It was a LOT of work to build it with the custom output shafts, carriers and bearings. Lots of machining, however, it didnt cost too much, maybe $300-400 in parts, inc the diff which i got on ebay (a 2000 torsen from a camaro).