Just having to control the lock up is all. Yup a lock up will lower the rpm by around 200-300 rpm. The tranny guys that I've talked to said driving a lock up converter un- locked up on the highway for a while will burn up the converter. Just what I've been told. I'm not a tranny guy.
I have a A500 for my 78 D100 and a A518 with the Ulta BB bell housing and new converter for my 72 Satellite. Both are lock ups. The A500 will be going behind a 360 so I need the conversion flex plate or a A500 lock up converter balanced for my 360. Ya the A500 has a lower first gear which is find by me
Good to know on the A500 only being a lock up.