LT's are a Chevy engine, predecessor to the LS series engines...

If you're talking about Ford's new modular engine, the 5.0 Coyote engine, they are a DOHC engine that put out 412 hp out of the crate in stock form and well over 600 with the Kenne Bell supercharger and still get 25 mpg on the highway with the OD transmission.

The stroker versions of the Chevy LS engine, like the LSX 454 do upwards of 500 hp out of the crate, and much more when tweaked and tuned. The LS 7 is 500 hp, the LS 9 is over 700hp and still more the 20 mpg.

Then there's the LS street rod engine that's even legal in California for Hot Rods.....

Heck yes they're going to have an impact!!!, most all improvements do!!!!