My father put an LS6 454 into his 66 GMC in place of the 6 cylinder.
I'm not into fads, and the LS craze is a fad. No LS will ever be installed into any of my vehicles if they didn't come with one from the factory. If someone else wants to do it, I'll let them, it's not my money. Thanks for the input though. The LS does make great power and gets good mileage, but again, fad.