Is it worth it ? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**Already Gone** · 06-10-2006, 07:02 AM

I have a 700R4 that I can put in my truck. My truck has a 396 and TH400 right now. I love the way my truck runs but would like better mileage and I know the 700R4 will increase my mileage especially on the highway.

Its going to cost about 800.00 to put the 700 in my truck and I was ready to do it then started to second guess myself..

I'm looking for opinions and pros and cons of the TH400 versus the 700R4 !!!!

**Hart_Rod** · 06-10-2006, 07:20 AM

It's win-win if the tranny is built to handle the bigblock. You get a Lower 1st gear (so quicker off the line) and then you get OD for highway cruizing. Just make sure it is built to handle the torque of the BBC and the TV cable is adujsted correctly.

**Boog** · 06-10-2006, 08:01 AM

You must also consider the rear end gear ratio. OD with a high geared rear can hurt mileage. Use something like Richmond gear calculator to see if the final drive ratio will yield better possible mileage. www.richmondgear.com

Longhorn Man · 06-10-2006, 06:06 PM

Boog beat me to it, and many simply don't believe this, but yes, an overdrive will not always help MPG, and can actually hurt it.

**Already Gone** · 06-10-2006, 06:11 PM

Quote:

Originally Posted by Hart_Rod

It's win-win if the tranny is built to handle the bigblock. You get a Lower 1st gear (so quicker off the line) and then you get OD for highway cruizing. Just make sure it is built to handle the torque of the BBC and the TV cable is adujsted correctly.

Thanks for the info. What do you mean by "handle the big block"? The 700 is from a 90 Burb that I wrecked. I have it documented that is only has 25,000 miles since a rebuild by alocal very reputable trans shop.. I dont race my truck but will occasionally drive aggressivley in traffic or pull away from a traffic light spiritedly.

Longhorn Man · 06-10-2006, 06:16 PM

he means the 700 isn't a very strong unit to begin with, and a big block is a torquey motor.

Rokcrln · 06-10-2006, 06:24 PM

The 700R4 is a great tranny when built right! I had one built by a local shop near Sacramento A.T.O. and it cost me $2800 and is guarentied for 700HP but only out of a small block!!!! Big blocks just have to much torque through out the power band of a 700. You need to go to a 4L80 if you dont want to be left on the side of the road during those traffic runs! Just my $.02

Kevin
LFD Inc.

Longhorn Man · 06-10-2006, 06:36 PM

naaa, 4L80E is way too expensive to set up. A TH400 with a gear vendors would be better, and cheaper.
Heck, if your TH400 is a strong well maintianed unit, you could go a gear vendors for about 1200 or so... not a whole lot more than the 700 numbers listed here, and WAY stronger.

You'll NEVER break a gear vendors, plus, you'll have a 6 speed.

**john** · 06-10-2006, 07:52 PM

If you want a little sticker shock look at the prices for gear vendor. They have gone up a tad. Look at price code D

http://www.gearvendors.com/prices.html

**clay68c10** · 06-11-2006, 12:41 AM

You can find 'em on fleabay for about a grand used.

shelby987 · 06-11-2006, 01:17 AM

that is true, if you are looking for a 2wd setup, and have some fabrication skills, you can always find some aux. overdirve setups that would bolt to the rear of your TH400.....personally I would stick with your TH400 and throw a couple hundred at getting an aux. overdrive.....the cost of beefing up your stock 700R4 plus installation......you could buy a couple cases of beer and an aux. overdrive.....and possibly trick some local members into helping you with the install :smile:

classicchev · 06-11-2006, 01:22 PM

I have a guy her in Calgary that is building my 700 for my 502 Ramjet the will handle all of the 585ft/lbs plus more. He will stand behind his work, as he builds many tranny's for local racers.

If you need his number, PM me.

Chevrolet4x4s · 06-11-2006, 01:59 PM

Would I see better mileage on a diesel 2wd (2.76 or 3.08)with a 700r4(lock up converter) or a turbo 350 or 400?Also would a 6 speed manual from a latemodel f body bolt up and hold up to a N/A6.5? would a stock diesel flywheel work which clutch would i use f body or truck?
Thanks
Shane

Longhorn Man · 06-11-2006, 02:27 PM

with gearing that low, you'd probably be better off without the OD.

Chevrolet4x4s · 06-12-2006, 11:30 AM

What gearing should I run?.......with 2.76s it would be running 150mph in overdrive at 3500rpm

with 235/75/15 tires
Shane

67ChevyRedneck · 06-12-2006, 11:36 AM

If you want to run an OD tranny (IMO) you should have a rearend with at least a gear in the 3.40's and if you do any towing or hauling a 3.73 would be best. A lot of new trucks with OD run 3.73's. My z71 has a 3.73 locking rear

Cars can run the higher gears, because they're more aerodynamic, weigh a lot less and run smaller tallers (effectively giving them a "lower" gear in the end.)

**Already Gone** · 06-12-2006, 05:59 PM

Thanks everyone for the thoughts. ideas and opinions on my transmission dilema. I think for now I'll take my TH400 get it checked out and serviced and use it for the time being. I'll tuck the 700 away in a corner of the garage (cause they dont deteriorate from sitting) and spend the 800.00 I was gonna spend on the trans swap on my lowered suspension..

06-10-2006, 07:02 AM	#1
Already Gone 70+ ( Old Skool Club ) Join Date: Nov 2003 Location: Saskatoon, Saskatchewan ,Canada Posts: 9,144	Is it worth it ? I have a 700R4 that I can put in my truck. My truck has a 396 and TH400 right now. I love the way my truck runs but would like better mileage and I know the 700R4 will increase my mileage especially on the highway. Its going to cost about 800.00 to put the 700 in my truck and I was ready to do it then started to second guess myself.. I'm looking for opinions and pros and cons of the TH400 versus the 700R4 !!!! __________________ 1972 C10 Custom/Deluxe 613 Highlander 406/700R4 1999 White Tahoe LS 4x2 with Z56 Police Package 1992 K1500 GMC Suburban Members I have personally met: MusicMan70 - HeavyD - ChewyChevy67 - StingRay -71SWB4x4 - 67 Burb - DeadheadNM - too much stuff - bc65 - das601 " Circumsatances Do Not Change Responsibility " " The Sky is not the Limit, Your Mind is." Marilyn Monroe .. RIP Charlie Watts 1941 - 2021

06-10-2006, 07:20 AM	#2
Hart_Rod ************* Join Date: Apr 2005 Location: Pensacola, FL Posts: 17,858	Re: Is it worth it ? It's win-win if the tranny is built to handle the bigblock. You get a Lower 1st gear (so quicker off the line) and then you get OD for highway cruizing. Just make sure it is built to handle the torque of the BBC and the TV cable is adujsted correctly. __________________ Rob - https://www.instagram.com/hart_rod_c10 As Iron Sharpens Iron, So One Man Sharpens Another. Proverbs 27:17 FOR SALE: DBW pedal bracket - http://67-72chevytrucks.com/vboard/s...d.php?t=651123 FOR SALE: Hood Brackets http://67-72chevytrucks.com/vboard/s...d.php?t=679945 1987 Silverado SWB - 34.5K original miles http://67-72chevytrucks.com/vboard/s...d.php?t=801834 1969 SuperBurb - http://67-72chevytrucks.com/vboard/s...d.php?t=200387 1968 Farm truck - http://67-72chevytrucks.com/vboard/s...d.php?t=358692 1968 SWB - http://67-72chevytrucks.com/vboard/s...d.php?t=551258 1948 Chevy - http://67-72chevytrucks.com/vboard/s...=122164&page=3

06-10-2006, 08:01 AM	#3
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 13,535	Re: Is it worth it ? You must also consider the rear end gear ratio. OD with a high geared rear can hurt mileage. Use something like Richmond gear calculator to see if the final drive ratio will yield better possible mileage. www.richmondgear.com __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver primer is finer 91 Chevy sportside, Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross

06-10-2006, 06:06 PM	#4
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: Is it worth it ? Boog beat me to it, and many simply don't believe this, but yes, an overdrive will not always help MPG, and can actually hurt it.

06-10-2006, 06:16 PM	#6
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: Is it worth it ? he means the 700 isn't a very strong unit to begin with, and a big block is a torquey motor.

06-10-2006, 06:24 PM	#7
Rokcrln Senior Member Join Date: Jul 2005 Location: Winters Ca. 95694 Posts: 4,843	Re: Is it worth it ? The 700R4 is a great tranny when built right! I had one built by a local shop near Sacramento A.T.O. and it cost me $2800 and is guarentied for 700HP but only out of a small block!!!! Big blocks just have to much torque through out the power band of a 700. You need to go to a 4L80 if you dont want to be left on the side of the road during those traffic runs! Just my $.02 Kevin LFD Inc.

06-10-2006, 06:36 PM	#8
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: Is it worth it ? naaa, 4L80E is way too expensive to set up. A TH400 with a gear vendors would be better, and cheaper. Heck, if your TH400 is a strong well maintianed unit, you could go a gear vendors for about 1200 or so... not a whole lot more than the 700 numbers listed here, and WAY stronger. You'll NEVER break a gear vendors, plus, you'll have a 6 speed.

06-10-2006, 07:52 PM	#9
john member #16 Join Date: Dec 1999 Location: Yuba City Ca. Posts: 3,618	Re: Is it worth it ? If you want a little sticker shock look at the prices for gear vendor. They have gone up a tad. Look at price code D http://www.gearvendors.com/prices.html __________________ john http://67-72chevytrucks.com/vboard/showgroups.php board vendors http://www.flickr.com/photos/1745471...7602865984234/ Last edited by john; 06-10-2006 at 07:53 PM.

06-11-2006, 12:41 AM	#10
clay68c10 Senior Member Join Date: Aug 2004 Location: Centennial, CO Posts: 2,991	Re: Is it worth it ? You can find 'em on fleabay for about a grand used. __________________ ClusterTruck: 68 C10 Bought in 89, wrecked in 03. Slow low $ rebuild started '17. 6.0 & TKO http://67-72chevytrucks.com/vboard/s...d.php?t=788602 93 K1500 Short Step, 350, NV4500, EBL flash ECU. Vortec heads & roller cam someday... 05 Jeep Wrangler Unlimited. 3” lift & 6-speed 02 E320 the insurance total “free car” 13 Tahoe LTZ

06-11-2006, 01:17 AM	#11
shelby987 Registered User Join Date: Mar 2005 Location: Just outside Durham, NC Posts: 894	Re: Is it worth it ? that is true, if you are looking for a 2wd setup, and have some fabrication skills, you can always find some aux. overdirve setups that would bolt to the rear of your TH400.....personally I would stick with your TH400 and throw a couple hundred at getting an aux. overdrive.....the cost of beefing up your stock 700R4 plus installation......you could buy a couple cases of beer and an aux. overdrive.....and possibly trick some local members into helping you with the install :smile: __________________ 1969 SS 350 Camaro Sold 2008 1970 3/4T K20, stock height with 33's, 250 I6, 3 on the tree, and locked front and rear 4.10's 1980 Chevy Malibu 2 dr Sold 2007 1993 Olds. Cutlass Ciera Wagon Traded 2006 2003 Saturn L200 w/5pd. D/D My list spans 5 decades with One common thread.....GM!

06-11-2006, 01:22 PM	#12
classicchev Senior Member Join Date: Nov 2003 Location: Calgary Alberta Posts: 1,936	Re: Is it worth it ? I have a guy her in Calgary that is building my 700 for my 502 Ramjet the will handle all of the 585ft/lbs plus more. He will stand behind his work, as he builds many tranny's for local racers. If you need his number, PM me. __________________ 67- 72 Parts collecter

06-11-2006, 01:59 PM	#13
Chevrolet4x4s Registered User Join Date: Nov 2005 Location: WV Posts: 227	Re: Is it worth it ? Would I see better mileage on a diesel 2wd (2.76 or 3.08)with a 700r4(lock up converter) or a turbo 350 or 400?Also would a 6 speed manual from a latemodel f body bolt up and hold up to a N/A6.5? would a stock diesel flywheel work which clutch would i use f body or truck? Thanks Shane __________________ 1993 K1500 350 5 speed 1985 K10 Silverado Vortec 406 5 speed (in body shop) "I been drivin' this '85 pickup truck Them buddies of mine call it a bucket of rust She's a little beat up but she still runs like the wind Yeah, kinda like me I been banged and bruisedBeen around the block a time or two But I'm runnin' like new goin' places I never been No, I ain't broke I'm just broken in" 1963 Dodge Townwagon(its amazng what 30 years and zero miles will do to a vehicle ) Member#20327

06-11-2006, 02:27 PM	#14
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: Is it worth it ? with gearing that low, you'd probably be better off without the OD.

06-12-2006, 11:30 AM	#15
Chevrolet4x4s Registered User Join Date: Nov 2005 Location: WV Posts: 227	Re: Is it worth it ? What gearing should I run?.......with 2.76s it would be running 150mph in overdrive at 3500rpm with 235/75/15 tires Shane __________________ 1993 K1500 350 5 speed 1985 K10 Silverado Vortec 406 5 speed (in body shop) "I been drivin' this '85 pickup truck Them buddies of mine call it a bucket of rust She's a little beat up but she still runs like the wind Yeah, kinda like me I been banged and bruisedBeen around the block a time or two But I'm runnin' like new goin' places I never been No, I ain't broke I'm just broken in" 1963 Dodge Townwagon(its amazng what 30 years and zero miles will do to a vehicle ) Member#20327

06-12-2006, 11:36 AM	#16
67ChevyRedneck Hittin E-Z Street on Mud Tires Join Date: Nov 2004 Location: Greenville, SC Posts: 23,090	Re: Is it worth it ? If you want to run an OD tranny (IMO) you should have a rearend with at least a gear in the 3.40's and if you do any towing or hauling a 3.73 would be best. A lot of new trucks with OD run 3.73's. My z71 has a 3.73 locking rear Cars can run the higher gears, because they're more aerodynamic, weigh a lot less and run smaller tallers (effectively giving them a "lower" gear in the end.) __________________ Jesse James 1967 C10 SWB Stepside: 350/700R4/3.73 1965 Ford Mustang: 289/T5-5spd/3.25 Trac-Loc 1968 Pontiac Firebird: Project Fire Chicken! 2015 Silverado Double Cab 5.3L Z71 2001 Jeep Wrangler Sport 4.0L 5spd 2020 Chevrolet Equinox Premium 2.0L Turbo 2011 Mustang V6 ~ Wife's ride American Born, Country by the Grace of God 1967 CST Shop Truck Rebuild! My 1967 C-10 Build Thread My Vintage Air A/C Install Project "On a Dime" Trying my hand at Home Renovation! 1965 Mustang Modifications! Last edited by 67ChevyRedneck; 06-12-2006 at 11:38 AM.



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06-12-2006, 05:59 PM	#17
Already Gone 70+ ( Old Skool Club ) Join Date: Nov 2003 Location: Saskatoon, Saskatchewan ,Canada Posts: 9,144	Re: Is it worth it ? Thanks everyone for the thoughts. ideas and opinions on my transmission dilema. I think for now I'll take my TH400 get it checked out and serviced and use it for the time being. I'll tuck the 700 away in a corner of the garage (cause they dont deteriorate from sitting) and spend the 800.00 I was gonna spend on the trans swap on my lowered suspension.. __________________ 1972 C10 Custom/Deluxe 613 Highlander 406/700R4 1999 White Tahoe LS 4x2 with Z56 Police Package 1992 K1500 GMC Suburban Members I have personally met: MusicMan70 - HeavyD - ChewyChevy67 - StingRay -71SWB4x4 - 67 Burb - DeadheadNM - too much stuff - bc65 - das601 " Circumsatances Do Not Change Responsibility " " The Sky is not the Limit, Your Mind is." Marilyn Monroe .. RIP Charlie Watts 1941 - 2021

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