chevy trans

[woodsracer144]

ok, so i got my brothers 86 chevy scottsdale 10, its got a 6 inch lift with 33's heddmen headers, magnaflow ehaust with true duals, holly 650 carb... the whole 9 yard...
now my flaw with this is that it gets like 8 miles to a gallon... and i think theres a 350 turbo trans in there right now, could i put a 700R4 in there and get better gas mileage with this or how could i get better gas mileage? the guy that owned it befor him was his buddy and the guy before his buddy used it to haul his race car around....

thanks
what about re gearing?

[Titanium]

the only improvement you'll see with the 700r4 would be with highway mileage.

[woodsracer144]

oh, how would regearing it in the axles or something?

[TCracin440ex]

well if go for a lower gear you are going to get worse mileage, if you go for a higher gear you will have less bottom end and more top

[woodsracer144]

so gearing wont really help me out...

[wvspeedfreak]

You are pretty much stuck with a gas hog.

[woodsracer144]

at what speeds would the 700R4 help me out on? i run about 60 all the time and im at 70 alot too...

[Titanium]

at speeds of 60-70 mph you would see quite a bit of improvement being that the 700r4 has one more gear than the th350. as for gearing i know that somewhere on the internet there is a chart that shows you what to re-gear your truck to so it will essentially have the original output to the ground so your speedometer is dead on too. If i remember right your supposed to regear your truck to 3.73s for 33's and 4.XX for 35's. i could be wrong though. but i am for sure that its possible.

[woodsracer144]

know where it was at? thanks

also will the TH700R4 bolt right up?

[KXRida]

Originally posted by woodsracer144
so gearing wont really help me out...

Gearing will help you out to an extent. You'll gain some mileage as well as making the truck a little more driveable/stock feeling with 33's. What gears are you running now? 3.73's? I need to run around a 4.56-4.88 to put my truck back to stock feeling acceleration and what not. Granted I'll get a decent increase in mileage when I do regear because I won't have my right foot stuck in the throttle. 4.56's would be a better hiway gear for me, but 4.88's would be a better offroad gear as well. You can calculate your gear ratio's need, or utilize one of the many gear calculators online. For smaller engines rule of thumb is 4.10's for 31's, 4.56's for 33's, and 4.88's for 35's. I do use my truck for some hiway to go to the tracks, so I'm debating if I want to go 4.56 or 4.88.

Regearing would be your cheapest/best bet as of now.

[woodsracer144]

to be honest... i have no clue what its geared for.. one use it to pull a race car trailer a while back and i dont think my brother geared it down or up...

and i have no clue what the 4:10 gears and all that means... is it a reduced ratio for 4 teeth on the motor/trans drive shaft and 10 on the end by the axle and houseing?

[KXRida]

Check and see if there is in axle tag on your front/rear axle first. It should have a 3(then a letter) then a 73 if it obviously has 3.73's. With the drive shaft disconntected, spin the pinion and the pinion should spin the number of rotations (4.10 times) to one full wheel revolution. That's kinda a cheap guesstimation way of figuring it out, but axles tags are always nice.

[JessetheKid]

th th350 is a 3spd...the 700 is a 3spd w/ overdrive if i am not mistaken. It will bolt right up to your motor, but i know chevy has many different splines for their transfercases. It may work but look into it. Also i am not sure on length you may have to move your crossmember and change driveshaft length. there is also some sort of electronics on the 700 that your 350 will not have. I looked into this a while back but just found that for the amount of driving i do it would not be worth it. Also the 700 is a much weaker tranny if i am thinking right. This may help ya
http://67-72chevytrucks.com/vboard/showthread.php?t=33266

[jonboy]

If your serious about it look into an Art Carr conversion for the TH350.

[slowguy17]

I have an 86 with 6 inches of lift 33 Trxus tires which are true 33s and 2.73s. Its has a healthy small block 400 with heads, single plain intake, 650 holly, 10.1 to one on compression, and so on. Cruisin down the road at 65 to 70 its turning about 19 hundred and getting about 12 miles a gallon. So what in getting at is if your hard on your truck a 700r4 wont hold up if its not built but the grany 4speed is practically unbeakable. But slow unless ur axels are high speeded. Also i dont know what cam your running but a xtreme 4x4 cam from comp will give you more low end power and dont have as much duration which help with milage.

[Titanium]

Originally posted by JessetheKid
th th350 is a 3spd...the 700 is a 3spd w/ overdrive if i am not mistaken. It will bolt right up to your motor, but i know chevy has many different splines for their transfercases. It may work but look into it. Also i am not sure on length you may have to move your crossmember and change driveshaft length. there is also some sort of electronics on the 700 that your 350 will not have. I looked into this a while back but just found that for the amount of driving i do it would not be worth it. Also the 700 is a much weaker tranny if i am thinking right. This may help ya
http://67-72chevytrucks.com/vboard/showthread.php?t=33266

The 700r4's aren't necessarily "weak". I dont remember what the kit is called but there is a kit out there that converts your 700r4 to where it no longer is electronic and is supposedly as strong as the th350's. I've seen it done on a couple of drag cars. And yes he is going to have to get a different driveshaft for sure. As for the transfercase ordeal im not sure about. If i were you and was serious about the 700r4 swap i would just pull the tranny and transfer case out of the same truck so you didnt have to mess with mixing n matching if you know what i mean.:chinese:

[KXRida]

haha you could always run a 351 mated to a C4 or small block C6! :p

[woodsracer144]

what ever i can do cheapes would be the best because after i get the boddy all done i would like to put a 5.9 cummins in it or a 7.3 powerstoke in it... one way or another a turboed diesel...

[stuftmunky2k]

you gotta think when you go switching trannys like that your gonna have 2 get your drive shafts. shorted and or lengthed. due to the fact the tranny is longer. that and regearing will help with the mpg. but still your turning bigger tires. your gonna have to live with it.

[KXRida]

Originally posted by stuftmunky2k
you gotta think when you go switching trannys like that your gonna have 2 get your drive shafts. shorted and or lengthed. due to the fact the tranny is longer. that and regearing will help with the mpg. but still your turning bigger tires. your gonna have to live with it.

Gear's help compensate for this, but yes you do have more rolling mass.

[Blue250X]

A 700R4 of the era should not be electronic. A 700 will help with mileage all around because of the overdrive and because the first gear is lower IIRC so it should get you rolling better too. It is a weaker transmission though. It also doesn't like not having enough rear end gear for the tire size.

[woodsracer144]

Originally posted by jonboy
If your serious about it look into an Art Carr conversion for the TH350.

what is the Art Carr?

how much do the gears cost to get it regeared? how hard is it? any harder then taking a motor apart?

[KXRida]

Originally posted by woodsracer144
what is the Art Carr?

how much do the gears cost to get it regeared? how hard is it? any harder then taking a motor apart?

Well all depends what gears you're looking at. You can get some Ebay off brand (nothing wrong with that) gears that will run you roughly $400ish for the front/rear depending on what axles you're running. You'll also need a master install kit which is roughly $30-$50 depending on axles, but this includes all shims and crush sleeves needed. The biggest things with gears are having correct pinion depth and backlash. Back lash should be roughly 0.007" if I remember correctly. It's been a little bit since I've regeared a vehicle. This can be found with a dial indicator. It's not rocket science, but if it's not done correctly, you could be potentially wasting your time and money. If not installed correctly, you run the risk of chewing the ends of the teeth off, lots of rear end whining, breaking gears, etc. If you've taken a motor apart, it's the same principle with a cam, well with the exception of chevy. With fords, you have to have the cam riding within spec on the cam gears or you'll just chew them up. Check into it, research it a little bit, and then go from there. A starting point would be to determine what axles you're running? My guess is a 10/12 bolt rear.

[snacob14]

If you really want a 700r then you will need to buy one from 85-87. And yes, 700's are a weaker transmission. They do have a lower first gear than any 3speed you would find for that year. Honestly though, its not going to get any better unless you gear the axles and throw the 700 under it. But after all that work you'll be around 3000 bucks into it if you go the cheap route (paying someone to gear the, installing the tranny yourself). I think you should just be happy with the setup you have now or sell the truck. If you're going to drive something big, you're going to have to suffer with fuel cost. With a short bed truck, with stock axles, you're probably running 3.08 gears. You'll have to gear it to 4.11's if you want to see some difference in gearing, but then on the highway you'll only be able to run 60 and you'll be screaming. I've built a couple of those chevys, they are fun, and cheap to work on, but they are no where near efficient when lifted. It wouldn't matter if you had a brand new chvy pickup. with 6 inches of lift and 33's you're only going to get around 10-13 mpgs

[woodsracer144]

its a long box, and i think its the stock rear end in it with the longer shaft... im gettin at my place this weekend hopfully...

i'll take a tone of pics and post them for you...

[yellow416ex]

the 700r4's really hate heat also, if you swap that tranny in it would be a good idea to get a large aftermarket tranny cooler

[KXRida]

with a 350 you should be making enough power to get away with running 4.1 0/1's. Regearing would be your cheapest/easiest route to go first.

[woodsracer144]

how much would it cost if i would take the truck and have soem one else regear it for me?

[KXRida]

Each shop differs. Make sure you look into a decent shop though. I know a lot of local guys around here that just slap them in an hour and call it a job. Definitely not the way to do it.

[fast_enough]

Originally posted by KXRida
Each shop differs. Make sure you look into a decent shop though. I know a lot of local guys around here that just slap them in an hour and call it a job. Definitely not the way to do it.

It doesnt take too long to regear, and if youve done it more than twice it comes pretty natural and doesnt take long and isnt hard to do a good job. But i say definetly regear, I would do that long before i would put a 700r4 in a decent truck.

[snacob14]

gearing will take between 1000 and 1200 depending on where you take it. And those would be good prices. Don't do it yourself, this is definitely not a doit your self job. It would be a waste of a few hundred to do it yourself.

[woodsracer144]

HOLY **** BOMBS i think i'll buy another axle and do it my self really solwly or something.. im not payin 1000 - 1200 for re-gearing! F that.

[KXRida]

$1000-1200? Please. You'll be looking anywhere from $400-$700 for gears. $500 for an install? No way. Like I said, some guys just slap them in, in an hour or so. I've done quite a few sets myself and I'd rather take my time, set it to within specs, and have it drive right and not have to rip it apart in 5,000 miles. I did an install for a guy last year. He supplied the axles, gears, install kit and I charged him $150 to do a front and rear. That's just me though.

[woodsracer144]

what would a extra axle cost for me to pick up? thanks even one with out gears or one geard for what i want?

[woodsracer144]

what would i want for gearing?

http://minneapolis.craigslist.org/pts/1008752178.html
http://minneapolis.craigslist.org/pts/1008577045.html
i would rather spend the money on a axle and sell mine.... and just swap them out becuase that would be the easyest...

[woodsracer144]

http://minneapolis.craigslist.org/pts/1009771667.html
http://minneapolis.craigslist.org/pts/1007206258.html

[JForestZ34]

Originally posted by JessetheKid
th th350 is a 3spd...the 700 is a 3spd w/ overdrive if i am not mistaken. It will bolt right up to your motor, but i know chevy has many different splines for their transfercases. It may work but look into it. Also i am not sure on length you may have to move your crossmember and change driveshaft length. there is also some sort of electronics on the 700 that your 350 will not have. I looked into this a while back but just found that for the amount of driving i do it would not be worth it. Also the 700 is a much weaker tranny if i am thinking right. This may help ya
http://67-72chevytrucks.com/vboard/showthread.php?t=33266


From what I understand the 700r4 is supposed to be a stronger trans than the th350. They are used in corvette's and camaro's. Alot of people use them on there old project cars for a stronger trans along with the OD gear for better mileage on the highway..

James

[JForestZ34]

As far as the trans being electric I think that is for a electric torque converter.. I know the one I have in my 87 firebird it's only used for the lock-up on the converter.. I swapped the V6 for a worked 350 with the 700r4.. I love the set-up.


James

[KXRida]

Originally posted by woodsracer144
http://minneapolis.craigslist.org/pts/1009771667.html
http://minneapolis.craigslist.org/pts/1007206258.html

Try to find a stock replacement with the gear of your choice. If you're looking for 4.10's good luck unless they are aftermarket. A junkyard very rarely has 4.10's. Ford has a factory option of 4.10's so every now and then I run across a 4.10 D28/7.5 and pick them up for like $80 and sell them for close to $200-$300.

[Blue250X]

Originally posted by JForestZ34
From what I understand the 700r4 is supposed to be a stronger trans than the th350.
James

No.

The 700 is on of GM's weakest auto trannies behind a v8.

[JForestZ34]

Originally posted by Blue250X
No.

The 700 is on of GM's weakest auto trannies behind a v8.

I'm sorry I got that mixed up, I know the TH400 is stronger than the TH350.. That would be my weapon of choice.


James

[snacob14]

good luck if you're going to do it yourself. Have KXrida come over and help. I've geared many many vehicles, ten if we're counting. I've done jeeps, ford 9 inch rears, yota's and a few chevys. Thats what you'll pay to have it done. This is no easy task, you want someone who knows what they're doing. pricing, you're looking at around 170-200 per axle for gears, 60-100 per axle for install kit and then labor. Thats close to 1000 or more depending on labor and where parts are bought. Get it done right, once and never worry about it again. Believe me, you don't want to be tearing down the axle every 5k. If you want 4.10's already in an axle, you are going ot have to find some 3/4 ton axles out of a chevy, direct bolt in. They are out there, and can be had for a decent price, definitely less that gearing them your self. Look on craigslist, or any local 4x4 boards. Should be able to get a set aka 14bolt/10bolt for around 350 bucks. Junk yard is going to want more than that for them, but you can definitely find them online for a good price. I"ve got a 14 bolt behind my shop right now if you were closer you could have. Good luck man, call around and find some shops to gear it and get an actual quote, then you'll know for sure.

[woodsracer144]

yeah, i think im gonna just buy another axle, houseing what ever you wanna call it... how do the dana 44's and dana 60's and all them differ? and whats the diff with a 10 bolt and a 14 bolt?

also could i put a GM diesel right in there or would i need modding? do the diesels run the 350 and 400 trans or what do they have? are they the same bolt up? i really am a diesel freek... i love them but sadly dont know to much about them... startin to learn alittle...

i have a few other things i have to take care of before i can tear in to the scotts... i'm workin on my quad right now... and tryin to sell my extra truck...lol

any one know of any older body style chevys that have a turboed diesel in them that are in good shape... i know that the first GM diesels where pretty much a gas 350 just converted over... and i've heard they were doggy when it came to power....

i like the look of them stacks... i would like those stacks and a drop visor of a Simi when im done... but thats later on... thanks for the help!