I've watched some Mountains Garage videos on YT. The guy is very knowledgeable on the TH400 and Power glides. I've only really watched his transmission videos, but I think he's into drag racing?
Anyways, I seem to recall the Glide requires most internal parts to be replaced for it to handle big power, which can get expensive, especially if you swap to a different ratio geartrain. Do you know what ratio yours is?
OTOH, the TH400 doesn't require much. And the few upgrades can come from stock replacement parts from the 4L80e.
He did a video comparing the two units. I'll see if I can find it if you are interested.
Just a thought. Either will work. Is the truck going to be fast enough to require that SFI-certified bell housing? I see those guys running that, but don't know what triggers that requirement or if it's just 'cause it looks cool... I'm just a stock guy, so I don't know a lot of these things.
I believe I've mentioned this before, but don't remember if on your build thread or not. Probably have, and forgot...
Edit: Here is the video I was thinking about; not really a comparison video as I mentioned above. In the beginning he talks about it.
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