this is what i have now 38" w/ 456 ratio and 465 tranny. when I'm doing 50 my rpms are about 2000 but if i put the 47s on it will be doing about 1600. now my question is will this lower my rpms too low. the set up now limits me to about 70 mph, with the 47 I'm think more bout 85 not saying ill go that fast but when on the highway when the speeds 65 I'm pushing the engine to hard so it will help me out there. but my main concern is on take offs, I'm thinking ill have to use Granny allot more than b4. any help on this situation would be helpfull