Best every day tranny with OD??

[swcu_21]

I am looking to change out the tranny on my 86 GMC long bed truck.   I have a month old 350 crate thats supposed to be pushing 290 hp and 2.73 rear end.

Currently I have a SM465 4 speed as a stop gap for a blown automatic in the truck. zieg85 mention adding a New Process 833a, 4 speed stick with .73 OD.

What is the best tranny option for a 24 mile daily commute with several traffic lights and one that would be easier on the gas tank 65-80 mph? I am definitely leaning to a manual, but have considered an automatic like the 200 r4. Hopefully I can get this figured in time to make the change during thanksgiving with my dad.

Any Ideas would be greatly appreciated, I'm definitely a newbie when it comes to building a solid truck.

[Captkaos]

What are you getting now for mileage and what are you hoping to get?

[zieg85]

700R4 auto almost has the same ratios 1st through OD as the A833.  Either one may work at 80 but your final drive ratio in OD is just under 2.00:1.  Your engine will probably be only turning 1400 rpms at 65 on stock height tires.  If your rpm's are a dog with your cam set up at the lower end you may end up using more gas just to keep the engine going.  I know that is exactly what I am going to do for my application on my 86 which will be just a cruiser anyway but I have basically a stock cam in mine.  I may only use the first 3 gears but not much options getting a 2.73 gear rolling with a stock type application.  I am unsure of the first gear on the 200R4 but I think it is close to the TH350/TH400 which is kinda long in the tooth with the high rear end.  M20 has a 2.56 first and the M21/22 has the 2.21 which usually needs at least a 3.55 rear end.  The saginaw has high 2's but not suitable in a 1/2 ton truck IMO.  They all share almost the same case size and with the exception of the M22 use the same slip yoke off the trans.  My $.02  There are probably other GM transmissions I am unaware of but the A-833 came stock and if you can find one with the original hurst shifter in good shape fits well with a bench seat and looks better with stock Suburban buckets. I have not looked into the NV3500 5 speeds but would also be a neat install assuming your 86 stick conversion is using a hydraulic clutch.  OK I'll shut up now....

[swcu_21]

Well at 70 im getting about 15 mpg, ideal RPM range is about 55mph, but you can't get anywhere at that rate. I travel from Alabama to oklahoma every couple of months and that makes it tough, I would like to get around 19-21mpg at 70. 9.5 hrs at 70-75 mph avg is pretty rough on the engine I would think with the current gearing. I don't mind the tranny set up for around the city too much I probably get around 12 mpg. I really just want the OD for the frequent road trips back home. So maybe the NP 833A is the answer, how much would a nv3500 improve a smoother drive in the city?

How difficult is it to set up the 700R4? I have heard that you have to get the linkages just right, being very new to working on trucks, could I install it? I like the idea of a computerless Auto. Would it be better to buy one of these used or get one thats been rebuilt?

My engine description:

This 350 is GM Performance Parts' value-leading crate engine, with 290 horsepower at 5100 RPM, and 326 ft/lbs of torque at 3750 RPM on 87 octane fuel. Its power will provide great durability with a 4-bolt mains, PM steel rods, and strong cast aluminum pistons. The camshaft has .450" intake and .460" exhaust lift with hydraulic flat tappets. The cast iron cylinder heads have 1.94" intake and 1.50" exhaust valves with 76 cc combustion chamber. The heads have the conventional 12-bolt intake manifold attaching design used from 1955 through late 1980. This 350 engine is not intended for marine use, and should be used in 1979 or earlier pre-emissions street vehicles or any off-road usage.

I have a Edelbrock 600cfm carb and an Edelbrock RPM Airgap intake on it. I am considering moving down to the performer series intakes for increased lowend torque, but I love the power you have at higher rpms on the road. I guess what tranny I get will help make this decision.

Rear tires are 31x10.5 R15 and current setup on the tranny is hydraulic clutch.

[zieg85]

Most, not all, A-833 has a different bell housing bolt pattern which your Hydraulic bell housing should have both.  That is a fairly hard item to come by if you have the older manual clutch, been there done that.  Drive shaft will have to be made to fit unless you can find one on a 3 speed or the 4 speed OD A-833.  Transmissions are not as hard to find as the proper shifter, again been there done that.  I have collected parts and pieces over 5 years but my greatest find was a complete truck with one in it.  If you have a tach and know what rpm you are when at 70 mph multiply that number by .73 and that should be the rpm's with the A-833.  With 255/70R15's mine calculates to 1612 rpm's at 70 in overdrive with the 2.73.  Your 31's should be slightly taller reducing the RPM's a little.

[swcu_21]

After having a local Mechanic keep an eye out the NV3500 and the New Process Tranny yeilded nothing but dissapointment, I may go with the Tremic TKO 500. Has anyone used one of these in a truck like my 86? Could I use the current tranny mount and just move it? I know it will require a new clutch(26 spline input shaft), will I have to get a new preassure plate? Also could I use the Bellhousing that is on the 4 speed now? I am trying to get a basic idea for a budget on the project. The tranny is about $2200 shipped as best as I can find and a new drive shaft will be about $300 according to a local hot rodder. Too many no could bury this project pretty deep!

Thanks,
J

[swcu_21]

All,

After weighing my options I am going with the 700r4. The NV4500 looked good but the was a little pricey new. I found a core and flex plate on Craig's list, this will save some money for sure.

My truck originally had a TH350 in it before being converted to the SM 465. All linkage elements were removed by the mechanic that made the swap. My truck has a tilt column. I have a couple questions about the automatic shifter linkage.


1. Do i need a new column to go to the 700r4?
2. Column shifter lever was removed, are these interchangeable with other year models?
3. Is the shifter linkage the same in the 700r4 and the TH350?
4. If I the column isn't compatible, what is the best floor type shifter to use? I saw the specs for a console that included one of these.

Also I will have a local auto shop install a stage 1 Jasper transmissions remanufactured 700r4, are these transmissions of good quality? They are supposed to have a 3 yr/100,000 mile WTY.

Thanks,

J

[malibu795]

at same cost you could put a Gear vendors over drive unit on the back of the SM463 .78 OD ratio..

1. new collum.. shouldnt unless you cut hte tab off
2. yes.
3. dont think so
4. B&M, need a 4 speed floor shift will come with a cable to attach to the shift shaft on the tranny..\

jaspers is usually a good rep shop.. stock 700r4 should have no problems with a 290hp 350..... i would look as up-dated.. and over build the tranny later... 350-400 area.. it migh start hateing you...
stall i would look at a 2000-2400 convetor... help off line accel.. and not bog the motor as much... TCC will allow you to cruise at low rpm with no slippage.
with a 700r4 OD is .70.. wiht 31" tires and 70mph your cruising 1500rpm... that is pretty low for said motor.. BBC you could get away with it.. not a basic 350
now.. change gears to 3.42 with the 700r4.. @ 70 you looking at 1800rpm..
currently with the sm465 31" tires and 2.73:1 gears 70mph is ~2000rpm
19-21mph....@70... that aint easy..
1. that motor your looking are ideal range between 2000-2500rpm cruising..
2. the truck is a brick in the wind.. faster wont help mpg
3. lowering the truck ~2" or so would help mpg..

[swcu_21]

Malibu,

Thanks for the reply, I dropped by the Pull a part in birmingham and realized I didnt have enough information, Cart before the horse I know. I am running a set of 10.5 wide 15" rally wheels, what would be a good lower profile tire to add? I was planning on dropping the tire size with the addition of OD. Is the a size or brand you would prefer?

Thanks,
J

[malibu795]

some were around a 28" tires..

as for brand... i have been runnign cooper ATR with good results.. but dont know if you can get them below 30"

[Captkaos]

Just swapping to the 700R4 is going to give you better mileage over the SM465 with no other changes.
Lowering a truck changes NOTHING as far as gas mileage.
Any tire manufacturer makes good tires, it just depends on what you want.  Factory size for our trucks were 235/75/15 which are roughly 29" tall.

The location of the frame lever on a 700 is a little different than a 3 speed auto.  If you are missing all the parts, I would just source all of it out of a donor.

Call Stinnet Transmissions in Birmingham and ask them if they have a rebuilt 700R4 or how much it is to rebuild one, get it built and then swap it.

[swcu_21]

Thanks Capt,

I was think that there would be an improvement, the shifting and gear set in the stick is pretty rough. I was already thinking about lowering tire size, there is too much side wall in these 31"s for me. Are there any more auto salvages worth going to in Birmingham open on saturdays? Most of the trucks and burbs I saw at pull a part had no transmission.

Thanks,
J

[Captkaos]

They generally pull all the good stuff out of the trucks at pull a part (or so it seems to me).
Are you looking for a used transmission to build or to just replace what you have?

These I know are open then, they are near my house.
Jefferson County http://web.userinstinct.com/1395636-jefferson-county-auto-parts-salvage.htm
Frankies Auto Parts http://businessfinder.al.com/853428/Frankies-Auto-Parts-Birmingham-AL
City Auto Parts http://www.cityautopartsal.com/

I am not 100% sure on this one, but you could call and ask.  They may have converted to all late models, but...
Spradlin Auto Parts http://businessfinder.al.com/841714/Spradlin-Alan-and-Johnny-Auto-Parts-
Inc-Birmingham-AL

Where are you coming from/Located?  I may can tell you some other places, but these are in Birmingham/Bessemer area.

[swcu_21]

Thanks Capt,

I am in the Huntsville/Decatur area, everybody I have called up here are closed on the weekends and most don't have anything that would work.  Yeah it seemed like there were very few transmissions left for sure, there was one that could have had what i was looking for but i couldn't get a positive id. I will call those salvage you mentioned about what parts they may have.

I origanally had a TH350 in the truck, so i need the shifter linkage and the drive shaft for the 700r4 to fit in my lwb 86 gmc truck with a 350 sbc. I was able to find a used 700r4 for a core/rebuild and flexplate for cheap on Craig's list local, but still need the linkage and drive shaft. I still have the drive shaft for the TH350, could I have that cut down or would it be best to have one built from scratch?

I am leaning towards the Jasper remanfactured 700r4, I have not worked with any transmisions so I don't know if my everyday driver is the place to start. Plus it has the 3 yr part and labor wty.