Can it be done without modifying the trans tunnel? I saw that Hurst had scattershields for the SBC's, but of course the Pontiac is a little special

It's for my father's car, he wants to keep the manual linkage and doesn't want to modify the body at all. Currently has a Muncie 4 speed w/console. I would like him to go T56, but if not it sounds like the TKO600 will be behind door #2. It cruises at about 3700 RPMs, not too enjoyable for long trips.
Seems like Liberty and Hurst seem to be reliable vendors, is there anyone else I should look into or stay away from?
Thanks everyone.