Thanks for the inputs.
I looked at Hurst Driveline Conversions, but they don't have a complete kit for my application (no cross member, I must admit the Hurst name alone had my attention). Choice is down to Silver Sport Transmissions or American Powertrain. I know AP has bad Yelp reviews, but Better Business Bureau gives them an A+ rating (4.78 out of 5.0). AP tells me they do orders of magnitude more Tremec kits than any other company. I checked another forum where AP news was mixed: both very good and some bad. AP uses a QuickTime bellhousing, while SST uses a GM 621 (which is a reproduction of a SBC) that requires a Magnum adapter plate for the Tremec. Costs were roughly the same after arm twist of AP for free shipping like SST offers. ( As an FYI: Hurst costs were about the same as SST and AP). I've set aside the quality aspect, since I'm not sure how to evaluate it. I just got an update from SST today that for 2018 orders they are implementing a 3 year warranty, which at least alludes to confidence in their products. I could not find any bad news about SST.....that's almost too good to be true. The bad AP feedback has my attention and has me concerned.
Still noodling. Decisions, decisions, arrggg! I don't want to goon this up. I will tell whoever I choose, that I will say good things about them if deserved, otherwise I will do the opposite: innocent bystanders can read the postings and reach their own conclusions.
Sorry for long winded summary above. I will follow up later, with good news....I hope!!!.