The S806A differential tag is coded to a 1984-1986 Ford Bronco. You seem to be missing a digit at the beginning of he second line. It should read 308 88 6C03. This diff. has a 3.08 non-locked (non-posi) ratio. If it was a locked diff. it would have an L in it (3L08). The 6C03 is the plant code where the diff. was built. So your ratio is 3.06, possibly swapped from a bronco, or built near the end of production with a leftover bronco diff.
SOURCE: www.fordifiation.com
The differential on a 1986 Silverado can be replaced with any year differential from 1973 to 1987. The replacement differential must be either a 2-wheel drive or a 4-wheel drive, depending on the type that needs to be replaced.
what is the ratio of gears in a 1986 cutlass
Well, that's kind of a 'hit and miss' question if you will. There should be a metal tag attached to the outside of the rear differential cover. Remove it and take it to a Chevy dealer and they could definitely tell you what the gear ratio is.
That is your rear axle. It delivers the power to your tires.
4.10 ratio
6.9:1
The fill plug is on the end of the differential. To access this, you will need to crawl underneath your car, and lok at the middle of the axle. There are two plugs on the differential; a drain and a fill plug. The Fill plug is obviously the plug closer to the roof of the car.
it will probably be 3.73
20:1
An 1986 model Yamaha outboard requires a 50:1 ratio, roughly one pint of 2 cycle oil, to six gallons of fuel.
Differential, with 10.25 ring gear Rear..........7.4 pints Differential, with 8.8 or 9 ring gear Rear..........5.5 pints Differential, Dana 70 HD Rear..........7.4 pints Differential, Dana 60, 61 Rear..........5.9 pints Differential, Dana 70 EX HD Rear..........6.5 pints Differential, Dana 80 Rear..........8.4 pints This link should help if you Identify which you have if you don't already know. http://www.drivetrain.com/rearend.html Hope This Helps.
Mercury outboards of 1986 lineage require a 50:1 ratio. One pint of 2 cycle oil, to six gallons of fuel.