Putting up with a 3.08 rear gear is about the dumbest thing I can think of to do to a poor ol' six cylinder. About the only thing dumber is to use a 2.78 or even a lower numerically ratio.
I know that it is a major task to pull the entire rear axle just to change a ring and pinion, not to mention the expertise needed to accurately set up the gears for quiet operation- I cant help that. If finances cause you to be stuck with a far too low numerical rear gear ratio, then so be it. My only solution is to search the junk yards/ swap meets. Tom Lowe sets up 12 bolts I hear, maybe even 3.55 ratios!
On this forum I have continually read of people running much larger than stock camshafts, bigger than stock intakes with larger carbs that cause much losses of torque/ horsepower at the lower rpm ranges, actually advocate the very same tall ratios that keep the poor ol' motor mired down in those low powerless rpm ranges where it could not peel off the skin of a grape. Maybe a solution would be a granny low 3/4 ton truck tranny, but you cant shift them very fast, have big ratio spreads and are VERY HEAVY. The lack of power/torque at these lower rpm ranges demand the carbs to be tipping into the carb power circuits to produce enough ummmph to keep the vehicle propelled on level ground, possibly never getting enough airflow signal through the venturi to even abandon the idle circuit's usage.
What possible fun could it be to drive a vehicle with that kind of bottom end? You practically need to open the door, stick your foot out and give it some help to leave the intersection.
You gotta get to 30 mph before you can get up to 70 mph (which with 27" tires and 3.08 gears is 1150 rpm at 30 mph and 2684 rpm at 70 mph) Lots of single bbl model b rochesters when on the fast idle cams of their chokes can see 1100 rpms at "idle".
292s with 194 intakes (markedly smaller intake passages) and 194 carbs running 6.17 rear gears have unbelievable botton end torque, but are at the extreme other end of the spectrum. You would be probably ready to go into final drive wether PowerGlide or the highly taunted 200r4 with their ULTRA CLOSE gear ratios just getting through the intersection.
I have heard from school bus folks, dump truck owners, and others that run 'em that the 292s are a bit thirstier than the 230/250s. The fact that the stock 292 carbs are jetted richer for their tasks in life than their lighter loaded passenger brethren-this may be part of the problem.
Low numerical rear gears puts more load on your engine too.
later, gators
My truck has 30" Michelin's on it and will stay that way.
