I have a '63 Chevy C-10 that I have wanted to put a 5 speed overdrive transmission in for a good while now. It has a torquey 350 small block that I built for it and a Saginaw 4 speed that I really like with a nearly new Hurst competion Plus shifter. It also has a 3.73 gear out back that has me reaching for another gear that I don't have. I'm not looking for raves about how bad those trannys are. Well yesterday on Craig's I found a rear end out of a '87 4X4 C-10. Same width inside to inside, same 6 lug bolt pattern, bigger brakes, and 2.73 gears with limited slip-$100. With a 2.64 first gear I'm thinking it will still pull off from a stop OK, but this ain't some thing I've done before. 3.55 rear ends are as far as I've went before. What do you guys think? I THINK that I would rather try to keep my 4 speed, 5 gears just don't seem right some how.
You should be ok with off the line takeoff for normal driving, but dont plan on launching it at lights. Youre getting into break stuff territory, if it hooks up at all.
2.64 x 2.73 = 7.21 in first gear. Most people want 9.xx or more to launch a manual trans comfortably. Works OK with an auto, but methinks you'll not be totally happy with the abuse your clutch will be taking. Gonna feel like you're leaving in 2nd gear of your current combination ( or worse). vic
The current overall first is like 9.85 and first is all most too low to be useful. This carrier will take a 3.23 or 3.08 gear at least, the old one is tough to change to any thing else.
I'm using a 3:08 with a Saginaw in a light roadster and it works well. The first gear was usless with the 4:11 rear gear or whatever I had before, but the 3:08 is a good gear for that trans in my application. I would think it would work well with a 350 size engine.
If your acceleration away from the stoplight is compromised too much, consider a gearset for the Saginaw from a Vega. 3.11 low gear should be just about right with your car and the tall rear gear. Admittedly, it would require an R&R of the transmission, but not too many fabricated or expensive parts.
I have 3:55 gears in a 56 F 100 with a 301 chevy and a muncie 4 speed and I would not go any lower than that in my truck if I am on an incline i have to ride the clutch to get it going
T5's are coming down in price-I just picked one up for $80. If you shop around, you can find one on the cheap, too!
Was running a SBC in my 40 Ford coupe with Ford toploader 3spd/overdrive with Dana 44 rear end with 3:31 ring and pinion. Alright off the line and rpms where about 2000 at 65 mph. Will be running a 8ba flathead with some performance upgrades and a Ford toploader 4 speed with Jeep shifter modification. Will be changing ring and pinion to either 3:53 or 3:73 gear ration
Thanks for all the responses. I have just about talked my self into giving this a shot. If it doesn't work out the original rear will be easy enough to reset. Slow as I work these days it may be a while, but I'll post up about how this worked out. As for the Vega gear set, that is a thought-if I could find one. More to come.
I used a 2.79 / 8" Ford axle with 235/70-15 tires in a '47 Ford Coupe with a 276 inch Merc Flathead/'50 Merc trans a few years ago. I wanted a decent highway cruiser. It was a little sluggish from a dead stop on a hill but otherwise quite satisfactory. With the engine you have, and considering you don't seem to be planning to drag race, I think you will find it works well with the 2.73. Ray
I posted in another thread about how happy I was with the 700R4 and 2.73 gears in my OT Chevy truck. After putting a few thousand more miles on it I now have to eat those words. It's a slug and I can't stand it anymore, I quit using OD all together and my mileage didn't change one bit. It's going in for a 3.73 gear swap in a few days. Get an OD 5 speed trans and keep the gears, you'll be a lot happier.
I had an '87 chevy swb pickup that was a factory TH400 with a 2.41 rear end. It took a little getting used to but I actually took a liking to it. Not going to win any drag races but highway RPM's were great. It was just like driving a big old cadillac or something.
3.07 gears for that rearend might be pretty nice, getting into the 2s would probably be a bit much with the trans you have. I had a 66 suburban years ago, I found a 70s van rear with 3.07 gears, swapped the carrier and gears in, came out really nice. But I also had a 454 and th400 in it.
Saginaw four speeds had low gear ratios of 2.54, 2.85, 3.11, and 3.50. They're still not expensive (compared to any other G.M. four speed), so you should be able to fine tune your driveline without spending to much money.
You'll need about 500 hp for those 2.73 to be any fun. probably top out over 150 mph. hope them brakes are good.
I used to drive a 4000 pound olds with a 2.73 rear and a close ratio muncie - 2.20 first gear. This was behind a 400 with a lopey cam. Not the best combination for the 1st gear launch, but it was drivable and once it got off the line it was fine. Your truck is probably lighter, and your 1st gear is deeper. It is cheap and easy to swap the rear end. You can probably get your $100 back if you don't like it, swap the old rear back in, and re-sell the new one. I would try it and see how you like it. You really have nothing to loose except a little wrench time. A heavey flywheel would be a benefit in this instance, 30 - 40 lbs.
A 3.11 low gear Saginaw with a 2.73 rear would make a take off ratio of 8.49:1, which is very close to the take off ratio of a wide ratio Muncie and 3.42 gears.
That is a good combo, but those full syncro Saginaw O.D. transmissions are getting really hard to find!
Consider this an update to my "Tale of Woe". When I started to install the rear end I made a trip over to my buddy Saun's place to get a set of spring perches. and while I was there chewing the fat with him about this swap he says "why don't you just put in a overdrive?" I told him that I was not gonna spend two grand on a gear box because I'm too cheap. So he gave me a NV 3500 out of a mid 90's truck straight swap for the rear end and I got that in with the clutch master cylinder working off the original push rod mounted under the floor. That was last week end when I got her all buttoned up. First gear is like 4 something to one and it is a sure 'nuff truck transmission. I hate it. First gear is too low for regular driving and second is too high to start off in.Thought about using the 2.73 gear behind this transmission but 5 th gear will be useless at any thing under 100 mph and Saun has allready put it to work. Then yesterday just playing with it I romped on it pretty hard and "blew" the NV 3500. A loud bang and lube drooling out the new hole in the side of the box is not a good sign I'm sure. This week end I'm going back to the original set up. In the past I've had a plan with every hot rod I have built, but this old truck has had about 10 different directions gone on it. Another friend of mine, Keith who runs a transmission shop down in Alabama, has offered to set me up with a rebuilt 700R4 for cheap, $350 with the lock up converter and every thing I'll need to install it. Tempting ain't it? When I finally make up my mind about which way to go with this I'll either find another rear end, spring for a TKO 600, or become shiftless.
My 3.73's are in and DAMN what a difference!!! It absolutely spanks the 1-2 shift now, it pulls so much better on hills and in traffic and my mileage actually went up a little. I wish now I had gone with 3.90 gears.
I had a jag with a mild 350 / 350 and 2.sumthin rear gears, it was heavy, and off the line it was a slug! i would get something like what squirrel said, i think that would be a good compromise.. hell get the rear for $100 sell it for $200 and put lower 3.07 gears in the diff ya have.
I had that exact tranny and gear ratio in my O/T G body El Camino.It worked out fine for normal driving,as in older guy driver. The El Camino is probably 700 pounds lighter than the C-10,so it could be a little doggy in the heavier truck...or not...