A500 & A518 electrical connection ?

Bragging:
I stated in this post “if I ever finish my project”. Well my A518 out of a 91 van is in the car. The rated 3200 stall converter (for a 727) feels more like 2000, The 408 makes plenty of power to overcome rear 10” aspen brakes. I’m doing the flick the switch setup for the OD in the ash tray. Flip on while in 3rd-Drive: it goes into OD. Note: I modified the factory floor gate shifter so I DONT GO INTO REVERSE ROLLING AGAIN! The factory shifter has the standard positions: P-R-N-D-2-1.
Here’s the situation: when I forget and leave the OD switch in the ON position. From a stop he transmission will: Go through all 4 gears. With a quick jump from 3rd-4th. Manually moving shifter: when I get to 3rd or D; it just quickly goes from 3rd into OD. Of course with the switch OFF position it just doesn’t go into OD. Otherwise with it ON it pretty much acts normal just a quick jump passing into OD.
Once I figured out the nature of it, this became a feature I like on the street and not at the track! No big deal, just flip the switch to off and close the ashtray lid on track days.
With 28” tires 3:55 gears at 80mph my tachometer shows around 2600-2700 RPM’s.
Heck yea I love it. My best 1/4 mile et in it is 11:79 so far. I’m feeling a bit transmission heavy at the track. On the street it’s enjoyable to not be RPM screaming in town or on the highway. Typically I just let it quick jump into OD so it will basically be lope-ing along doing 45mph. My full exhaust with cutouts is quiet and you can converse in the car keeping along with traffic on the interstate. Even if it’s not the way others would do it. I like it. When my buddy’s ride along and the OD switch goes back and forth, we say “Race Car / Street Car and have a laugh. I hope my review on how my setup works helps someone else decide if they should go that route. It’s so worth it.