The Stovebolt Site Forums The Parking Lot Panels 'N Burbs t-5 and a 3:08 rearend

guys' drug home a 83' S-10 long bed today for $30 bucks. the reason other than the price was for the t-5 trans and the wheelbase being correct for my 52' panel(future project) the t-5 is for my 54' burb i just drug home. the problem of bolt pattern choice has come down to using a donor 77' nova for the rearend and the disc rotors for the front. i'm keeping the 235 and using the t-5 and just guessing the nova rear is 3:08 ratio is this going to be to high of a ratio for the t-5?anyone who has done the t-5 swap chime in and yea or ney the install of the nova rear.i do realize tire diameter will affect the final ratio and havn't gotten that far yet. just don't want to waste the time using the wrong rearend. thanks. FEEDBACK PLEASE.

I wouldn't use a 3.08 [if it is, don't guess, check it!] behind a 235 with any trans, too high for the low gears, never mind OD

Bill

most likely it is too high unless you are running 13 inch tires

what ratio with 235/60/15" tires would be "acceptable"? 3:31+ feedback please!

I'm not sure I'd jump to the conclusion that your 3.08 gears won't work out okay. I have 3.08 gears in my '55 1st Suburban and while it doesn't pull a loaded trailer very well, running around empty its fine.

I have an SM420, not a T-5, but if you don't pull a trailer and only use 5th on the highway I suspect you'll do fine.

If you do pull a trailer the T-5 is the wrong transmission anyway.

One of my other vehicles has 3.08 gears and an OD that drops the ratio to about 2 to 1. That OD gear isn't much good around town, but on the highway I'm loafing along getting 26 MPG from a 3000+ pound car that smokes the tires at will. Of course it won't pull a trailer either...

I'm also running the 3:08 rear in my 46 pickup with the T-5 and while I'd rather have a 3:50, this works just fine in my light weight pickup.

Prior to the T-5 trans I was running the Saginaw 4 speed so the 3:08 was fine. If I had a better ratio I'd change, but it's together and I like it.

It depends on which t5 you've got. They didn't all have the same gears. Get the numbers from the tag on the case and go to the Inliners website to find out which one you have. The t5 with the .86 overdrive might work fine with a 3.08 rearend.

216 - 302 motor it does not matter
the ratios are below
line up the columns to all 5 gears.

florida as well as kansas are better suited for a 3.08

CHEVROLET T-5 Borg Warner Transmission Ratios:
1st: 2.95 2nd: 1.94 3rd: 1.34 4th: 1 5th: 0.74
Tire Diameter 1: 28.5 inches
Rear Gear Ratio 1: 3.08:1
MPH
RPM 1st 2nd 3rd 4th 5th 6th
1000 9 14 20 26 36 0
1500 13 20 30 40 54 0
2000 18 27 39 53 71 0
2500 22 34 49 66 89 0
3000 27 41 59 79 107 0
3500 31 48 69 92 125 0
4000 36 54 79 106 143 0
4500 40 61 89 119 161 0
5000 45 68 99 132 179 0
5500 49 75 108 145 196 0
6000 54 82 118 159 214 0
6500 58 89 128 172 232 0
7000 63 95 138 185 250 0
7500 67 102 148 198 268 0
8000 72 109 158 211 286 0


Tire Diameter 2: 28.5 inches
Rear Gear Ratio 2: 3.43:1
MPH
RPM 1st 2nd 3rd 4th 5th 6th
1000 8 12 18 24 32 0
1500 12 18 27 36 48 0
2000 16 24 35 47 64 0
2500 20 31 44 59 80 0
3000 24 37 53 71 96 0
3500 28 43 62 83 112 0
4000 32 49 71 95 128 0
4500 36 55 80 107 144 0
5000 40 61 89 119 160 0
5500 44 67 97 131 176 0
6000 48 73 106 142 192 0
6500 52 80 115 154 208 0
7000 56 86 124 166 224 0
7500 60 92 133 178 241 0
8000 64 98 142 190 257 0


CHEVROLET T-5 Borg Warner Transmission Ratios:
1st: 2.95 2nd: 1.94 3rd: 1.34 4th: 1 5th: 0.74
Tire Diameter 1: 28.5 inches
Rear Gear Ratio 1: 3.73:1
MPH
RPM 1st 2nd 3rd 4th 5th 6th
1000 7 11 16 22 29 0
1500 11 17 24 33 44 0
2000 15 22 33 44 59 0
2500 18 28 41 55 74 0
3000 22 34 49 65 88 0
3500 26 39 57 76 103 0
4000 30 45 65 87 118 0
4500 33 51 73 98 133 0
5000 37 56 81 109 147 0
5500 41 62 90 120 162 0
6000 44 67 98 131 177 0
6500 48 73 106 142 192 0
7000 52 79 114 153 206 0
7500 55 84 122 164 221 0
8000 59 90 130 175 236 0


Tire Diameter 2: 28.5 inches
Rear Gear Ratio 2: 4.11:1
MPH
RPM 1st 2nd 3rd 4th 5th 6th
1000 7 10 15 20 27 0
1500 10 15 22 30 40 0
2000 13 20 30 40 54 0
2500 17 26 37 50 67 0
3000 20 31 44 59 80 0
3500 23 36 52 69 94 0
4000 27 41 59 79 107 0
4500 30 46 67 89 120 0
5000 34 51 74 99 134 0
5500 37 56 81 109 147 0
6000 40 61 89 119 161 0
6500 44 66 96 129 174 0
7000 47 71 103 139 187 0
7500 50 77 111 149 201 0
8000 54 82 118 158 214 0

I tried the 3.08 in my 54, 1956 235, single Holley/Weber, w/Fentons with a .72 T5 and a 28.5" tall tire. It was great around town as a 4 speed but you had to be running 65-70 to get it into the torque curve and it was very flat....no pickup and the engine labored. I went with a 88 Camaro with a 3.42 and built my 1960 dual Carter/Weber, Fentons, engine up for low end grunt.

Around town you can use 1-4 and drop down to 35-40 in 4th.....slide into 5th at 50-55 and you're good to go. Don't have any real lugging.... down to 45 mph in 5th. No downshift necessary to run back up. She's happiest at 65-70 at 1900-2000 rpm's in 5th. I'm working on getting my fuel mileage up to 21+ and have no doubt that I can better that with a 65 mph cruise.

With the 3.42 setup at 65 mph cruise, she's just purring along....plenty of throttle left up to 80 but up there the wind noise and aero package (brick) make for some white knuckle driving....but it's there!!!! All under 3000 rpms.

I considered popping in a .86 T5 but with the 4.03 1st gear you'd be wound up pretty tight at 10-15 mph. I see no need to stress a 4 main engine that by design, was set up for low end torque. Cutting down tire height gives you about 100 rpms per increment and the stock 235 works well at 1600-2300 rpms.

I just couldn't see any sense in having an OD transmission that wouldn't give you a chance to cruise in 5th. IMHO I would recommend a 3.42 as the lowest number (tallest) ratio....a 3.55 or 3.73 if you live in an area with long hills or plan on pulling a load. Hope this helps!

Dave

thanks guys! i have to pull the trans and see what od. ratio is the truck is a 83' so according to the t-5 id chart(without checking tag) it's supposed to be a .86 5th gear. just want to drive this thing at least to one show this summer. GITTER' DONE!

You've really got to check the tag...the numbers stamped in the case are not going to tell you the OD ratio.

If the original S10 truck was a 4 cylinder you can pretty much bet it was a .86...if it was a 2.8 or 4.3 V6 I'd bet a .72. A quick way of determining the ratio on the S10 NWC transmission is with the transmission in 5th gear, mark both the input (front) and output (rear) at 12:00. Turn the output shaft (rear) 1 full turn (360 degrees).....and watch the front (input) shaft......if it turns over less than 3/4 (270 degrees) of a turn it's a .72....if it turns more than 270 degrees...it's a .86.

This should help you ID your T5 if you don't have a tag.

I've been running some numbers...if it does turn out to be a .86 and you're running a 28" tall tire it might just be fine with the 3.08. The key is to remember that the stock 235 makes good power between 1700-2400 rpms and that's where you want to keep it. I use this calculator:

http://csgnetwork.com/multirpmcalc.html

I use the bottom calculator as it is more accurate. I hope this helps.

Dave

I'm using a Nova rear in my '42 1/2PU with a T-5/235., The 3.08 was tough...couldn't get up a steep driveway w/o smelling the clutch and forget about 5th gear!. I switched to 3.55 rear and am pretty happy, but 1st is rather low. If I was going to do it again I'd probably go with a 3.31 or 3.42. By the way, I converted the the 5 lug set-up to 6 lug so I could mount my artillery wheels. Good luck.

well i'm going to put the nova rear in and if it is too tall geared i can always switch it with shorter geared rear, i have access to a few. main reason for the nova is i prefer to "use up" the donor car or they end up getting hulked. i can always use the 3:08 rear (if it doesn't work out) in a diferent truck with a automatic trans.

i have a 54/..235 with 2.73 nova rear and 215/75/15 tires and i am satisfied. also have dual carbs and fenton headers. i live in realitivly flat country. ron

I am planning to use a T5 behind a .030 over 292. The rear end I will use is from a 68 GMC and I think the ratio is around a 3.22. This is going into my '53 1/2 ton. I would like to find a 3.07 because the 292 is such a brute that I think it will handle the over drive. With the price of gasoline I am trying to get a few more mpg. Don

Don, from 3.22 to 3.08 is probably only a 100 RPM change at 60 MPH. Run the numbers on one of these online gear calculators. With truck tires you're gonna be pretty high already. In my car I have a trans. high gear of 0.73 & a 3.08 axle. My 292 motor pulls this quite well, but another consideration is low gear for take-off pull. My trans. has a 3.09 1st gear. It starts off OK but I have a 3.36 axle gear I want to try someday. I suspect the low gear multiplication factor will outweigh the small top gear change. In O.D. my tach reads 1500 to 1600 keeping up with normal traffic on a 55 MPH highway now. In direct gear (1:1) it reads 2100 to 2200. I have no speedo so this is the best example I have. Try what you have already, you're gonna love that 292 pulling power.
Doug

Doug
I had that 292 (stock) in a full size '76 Blazer mud racer back in the early '90s and loved it. I could run in high range on the transfer case and never run out of power where most others had to use low range so that they wouldn't run out of power. I plan to make the swap on my '53 this winter. Don