gearing vs mpg

skycuda67 said
the cam im runnin is a 284/484 purple power range 2200-6400 so ya i cant really get too low there :/. like i said 2.93's will cut me down to 2500 and so 2.76's would take me down to...carry the one... about 2300...eeek

mshred said
i never even thought of this before for my 5 speed swap...im running the same purple shaft 284 duration/ 484 lift cam in my 340, and in 5th gear i was planning to cruise at 65mph at 2100 rpm (with 3.91 gears and 28 inch tall tire)...from what i understand, the overdrive will be useless here because my cam isnt in its power range and thus still sucking back lots of gas in order to constantly cruise at that rpm?

wheres that cam cleaning up for you guys? the 509/292 i was running didn't clean up until just after 2200rpm or so. i was running 3.91 gears. dropped it to 3.55 and it was just ok around town but better on the highway. was gonna do the 2.94's but did the math and it would have sucked around town. cool as hell on the highway but totally undriveable at lower speeds.