The Stovebolt Site Forums The Shop Area Driveline t-5 with a s-10 3:08 rear

i got a factory t-5 from a 89 s-10 and a 3:08 rear(?) from a 88 s-10 any idea how its gonna run ??

Terrible!
Jerry

For years the standard rear end for an OD was 4.11. You can fudge on this down to 3.73 if no load hauling or trailer pulling is in the picture. T5's had several OD ratios from about 18% to near 30% so you need to find out what you have. If you have a 30% then take 0.7 x 3.08 and you get 2.16 for a final drive ratio in OD. You didn't mention your engine so if it's a 502 big block with twin turbos then it can handle it.

If you have a 502 big block your going to bust that T-5. The T-5 is a good alternative, just make sure you get the right combination.

It all depends on what engine you running & the o-drive ratio of the T-5. A lot of the late 80,s & early 90,s T-5 trans. used a .86 o-drive. It might work good if you don't have a real strong engine.

im running the original 216 for now, planning on a 235or bigger 6 later on

You'll have trouble making that one run above 3rd. gear. 4th. is direct drive, which would work with the 3.08 on level ground, but would accelerate very slowly, if at all and would have teouble on any sort of hill. 5th. gear would be a total wasted effort- - - -not enough torque from the 216 to maintain speed, even on level ground, most likely.
Jerry

I second what everbody else has said. Not a good combination for sure. However, tire size might also come into play with your calculations.

2000 rpm is a good place to be at 60 mph for a 235 6 cylinder motor. 3.08 gears with 26 inch tires (205/70r15)and a .86 od put you pretty close to 2000 rpm at 60mph. Most of us run taller tires on our trucks.

I prefer lower gears for better acceleration and grunt. I currently have 3.70 gears with a .73 od in my truck, but will be changing the gears to a 4.33:1 ratio to get a little more grunt. The 3.7 gears worked well with 28 inch tires (275/60R15) but do not work well with my current 31X10.5R15 tires.

There are a lot of variables to consider when building these trucks including but not limited to the following
Size of truck
Size of tires
Rear end
Gear availibility
Motor
Transmission
How it will be used... work truck? daily driver?
Personal preference
budget
etc.

What might be "gold" to one may be "crap" to another.

John

3.08 gears are too high for the 216 without the o-drive. Like Big daddy says it would probably work ok with a 235.

I have this ratio but with a 261, the trans is great for lots of reasons but I've only had her in OD gear on a few occasions. Just went to a less tall tire on the back but at next opportunity I'm going to around a 3:50 rear end ratio.

how about if i install a 3.73 ring and pinion from speedway motors in it??

That would be a much better choice. Be aware that most of the racing type R&P sets will have a little bit of gear noise when run in a vehicle with a moderately quiet exhaust system. When my son's Dodge Ram broke a pinion gear shaft, we replaced the gearset with one from Richmond Gear. It ran and pulled well, but I was never quite able to adjust the whine out of the gears, even after doing a lot of measuring and tooth pattern checking.
Jerry

A little personal experience. My 53 GMC was originally set up with a 228 and S10 T5. I checked the Hollander and found that all S10's with T5's were equipped with 3.42 rear gears (but 14"tires, remember)..Anyway I set up my Camaro rear end with 3.42s and all was well. Since then I've installed a hot rodded 270 with a Camaro World Class T5 which has the .72 or .73 Overdrive. Still works well, but I think the 3'73 rear gears might get the fuel mileage up over 20 instead of 19.6. Im turning about l850RPM at 70 MPH (verified by GPS) I feel the engine would like it better if it was turning about 2000 at 70 MPH.