Definitely light argent silver on just about everything in 1970 - rocker panels, Rallye wheel center caps, front grill, rear panel above lights (Challengers), etc.
Katfish nailed it! People run out and buy expensive torque convertors all the time when building big torque motors when they could have used a slant 6 convertor that everyone thinks is a dog. For certain years, the slant 6, 340, 383hp, and Hemi all used the same basic factory torque convertor.
Is it just me, or does the stock shaft (also forged!) look bigger in diameter? Even the threads look bigger. Could be just a two dimensional photo playing tricks.
You did grease the center shaft/pin and all the sealing rings in the front/kickdown servo, correct? The grease will help it function during the air test. And yes, the fluid is thicker than air.
Really, with STP oil treatment and the cheapest oil out there would work. The main thing is the extra zinc and phosphorus. And the proper brake in mentioned above.
Rons340, on BillJ's steering column, someone welded some kind of sleeve onto the original steering shaft. He's is no longer collapsible. That's my point.
Personally, I would use Valvoline VR1 for initial startup. I'm not sure all Royal Purple has zinc and phosphorus and you need that for flat tappet cams.
And be sure to prime the oil system with a long hex shaft and drill motor while slowly cranking the engine by hand. Then drop in the...
Whatever's cheapest! Seriously! I've had Walmart Supertech in my 70 Challenger for about 15 years now! You can even run Ford Type F fluid in a torqueflite! The best thing you can do for any torqueflite is run some kind of auxillary cooler and a deep pan for the fluid.
My 2¢: From a safety aspect (think frontal crash) I'd go with a correct used factory steering shaft. Second choice would be the Flaming River shaft. I think the Flaming River columns use different wiring (GM?). Third choice is making what you have work, but it requires more fabrication and the...