Sidelight:
On level road at highway speeds, vehicle weight makes little difference in the power required to maintain a given speed. Aerodynamics make a huge difference.
Weight really becomes a big factor in acceleration, whether it's changing linear speed, turning, or going up and down hills. It's also a factor in the rolling resistance in bearings and tires, but is quickly overshadowed by wind resistance.

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"When you find a big kettle of crazy, it's best not to stir it." - Pointy-haired Boss

1964 Valiant V200, 225/Pushbutton 904
BBD, CAI, HEI, LBP, AC, AM/FM/USB, EIEIO

i haven't had 3.55s behind a slant yet, but my truck loves the 3.55s, and it only has 215/75-15s. if i run a 205/75-14 on my b-cuda, it would give me a 26" tire. would that still be a nuisance? man, i'm wanting to throw away my brand new R&P now.

sb

3.55 are fun around town and at the track but they are hard to drive long distances on the freeway. Using a tall tire with that low ratio is helpful. (I swap-on a shot tire when I get to the dragstrip)

I tend to change my cars over to the 8 3/4 "drop-out" rearends so I can do fast ratio changes. I put 3.55 in for the Summer when I race, then swap them out when Winter comes. With 3.55 & a 26 inch tall tire, my engine tacs 34-3600 RPM to keep up with 60-70 MPH freeway traffic, the ol' Slant is working at that RPm and the milage really suffers if I spin it higher.

As other have noted, 3.21 / 3.23s would be a better choice for a mostly street, some strip car. If you want to get a feel for what you will have when you change to the 3.55, drive your current combo around in second gear for a day. Be sure to do some freeway driving.
DD