I think the long rod motor creates a little more torgue, but would not be as evident on a light car such as a dragster, SO a tighter converter just might show improvment on the ET. I know you like to run a loose converter to keep the violence down in the first 100 ft.. Heck i'd put a 5500/5800 in it to see if it changed, the compression is not going to help on the top end unless you're running 8500 rpm.
JMO
Zip.