6 cyl Overdrive transmission - The 1947 - Present Chevrolet & GMC Truck Message Board Network

69gmc292 · 05-16-2010, 04:52 PM

I was just see if anyone has ever but a 700r4 or a 200r4 overdrive transmission behind a 250 or a 292. I drive my truck everyday and it would be nice to take the freeway sometimes without my trucks engine sounding like it is gone to come apart. I have though about a manual swap but i kinda like my truck as an auto

Wrenchbender Ret · 05-16-2010, 05:12 PM

It will be an easy swap if you already have an automatic in it. The hardest part is hooking the throttle cable up to the 6 cyl. carb.

72BlckButy · 05-16-2010, 07:49 PM

Quote:

Originally Posted by Wrenchbender Ret

It will be an easy swap if you already have an automatic in it. The hardest part is hooking the throttle cable up to the 6 cyl. carb.

Will it use the tranny member already there or will you have to pull the cross member and move it?

Same bell housing?

N2GMTrux · 05-16-2010, 10:42 PM

A 250 or 292 work best between 2000-3000 RPM range and depending on your gear ratio in your diff and tire size the fourth gear in the 700r4 or the 2004r would be to low (.70) I think... And would cause your engine idle down into the 1600 to 1900 rpm range in the fourth gear. Again you would have to figure your tire size and gear ratio to put you in the 2000-3000 rpm range.

cris well · 05-21-2010, 12:23 AM

i thought the 292's had a different bolt pattern at the engine/bell housing than a 250 or SBC-BBC.

i may be wrong.

**'68OrangeSunshine** · 05-21-2010, 06:31 AM

Quote:

Originally Posted by cris well

i thought the 292's had a different bolt pattern at the engine/bell housing than a 250 or SBC-BBC.

i may be wrong.

You are wrong, Sir.

292farmer · 05-21-2010, 06:34 AM

if i remember a member on this site said the gear ratio split on the 200-r4 works better then the 700r4 with inline 6's not as big a ratio diff, between 1st-2nd. just thought i'd add that for consideration.

jablack · 05-22-2010, 09:58 PM

Does someone make a carb bracket for the detent cable?

raycow · 05-30-2010, 02:45 AM

I haven't seen an aftermarket bracket for the 6, but you can adapt the stock bracket used for the TH350 cable.

Ray

PanelDeland · 05-30-2010, 07:46 AM

You will also have to check Driveshaft length,crossmember placement(or get one if yours is manual now)and steering column or shifter will need to be adressed.You will also have to remove the existing crossmember if yours is manual.

69_hafton · 05-30-2010, 10:05 AM

Just to give you a ballpark number to look for, I'm under the impression from past info gathering that a 3.73 gearing set-up is what you're looking for in the diff. I've got a 4.10 and can comfortably go 65 with the overdrive (I think it's a .73?), but much more than that and the rpm's get uncomfortable.

There are probably other ratios that can be used, but they aren't as common, but maybe for more top end you could find around a 3.54?

Jacfourteen · 05-30-2010, 03:05 PM

I thought most of the I6's were geared low (4.10-4.56, or is that with the Manual?) so they should still have decent highway rpms even with OD. Anyways the rear gear is def an important consideration. I've heard that you can find OD trannies with the same overall length so the driveshaft won't have to be modified. I think you can use the same crossmember, but you have to move it back a few inches and redrill the mounting holes in the frame. Other than that it will be a pretty easy swap.

72gmcer · 02-23-2011, 11:35 PM

I was planning on putting a 700r4 behind my 250 also. Converting from a manual three speed. Does anyone know of a build thread that touches alittle more on the subject with maybe some pics. I'm new to the site and just want to say that this is the most informative site I've ever visited.
Posted via Mobile Device

jhyder408 · 03-08-2016, 06:46 PM

ist an old thread but I'm looking doing this... anymore input would be great. not necessarily concerned with gears but overall setup, manual to 700r4 in short box with a 250 6cyl

**Jurassic-1** · 03-08-2016, 07:49 PM

I was going to do the same thing on my 1966 truck. I have a 200r4 and asked Bowtie overdrives about the detent. He said there is not enough call for it and because the linkage is backwards it is more difficult to do. It can be done but the geometry should be on to not damage the transmission. I would also be interested if any one has install tips.

arkansas · 03-08-2016, 09:15 PM

I'm in the process of putting a 2004r behind a 250 in my 71. It originally had a factory T350 behind the 250 (odd combo but it's on the original spid). The 200 is the same length as a t350 so the driveshaft length is fine. The bell housing to mount location matches a t400 so you only have to move the stock crossmember to the t400 bolt holes in the frame so no drilling. Mine is all bolted in now but I've not tackled the cable yet. Still saving for FI for it first. The inlines were pretty torquey at low revs so I'm not too concerned about 3.73 being too high rear. Just pull it out if OD in town. I do that now in a Chevy coupe I'm running a 700r4 in behind a small block with 3.73 rear.

05-16-2010, 04:52 PM	#1
69gmc292 Registered User Join Date: Mar 2007 Location: tucson Posts: 71	6 cyl Overdrive transmission I was just see if anyone has ever but a 700r4 or a 200r4 overdrive transmission behind a 250 or a 292. I drive my truck everyday and it would be nice to take the freeway sometimes without my trucks engine sounding like it is gone to come apart. I have though about a manual swap but i kinda like my truck as an auto

05-16-2010, 05:12 PM	#2
Wrenchbender Ret Registered User Join Date: Oct 2005 Location: Overland Park, Ks. Posts: 5,208	Re: 6 cyl Overdrive transmission It will be an easy swap if you already have an automatic in it. The hardest part is hooking the throttle cable up to the 6 cyl. carb.

05-16-2010, 10:42 PM	#4
N2GMTrux Registered User Join Date: Jan 2007 Location: Fort Worth, TX 76133 Posts: 406	Re: 6 cyl Overdrive transmission A 250 or 292 work best between 2000-3000 RPM range and depending on your gear ratio in your diff and tire size the fourth gear in the 700r4 or the 2004r would be to low (.70) I think... And would cause your engine idle down into the 1600 to 1900 rpm range in the fourth gear. Again you would have to figure your tire size and gear ratio to put you in the 2000-3000 rpm range. __________________ ...try'n to be a little! This is a great site. http://67-72chevytrucks.com/vboard/s...d.php?t=157669 http://www.67-72chevytrucks.com/vboa...d.php?t=375640

05-21-2010, 12:23 AM	#5
cris well Registered User Join Date: Oct 2009 Location: atlanta, ga Posts: 318	Re: 6 cyl Overdrive transmission i thought the 292's had a different bolt pattern at the engine/bell housing than a 250 or SBC-BBC. i may be wrong.

05-21-2010, 06:34 AM	#7
292farmer Registered User Join Date: Nov 2009 Location: stoddard nh Posts: 693	Re: 6 cyl Overdrive transmission if i remember a member on this site said the gear ratio split on the 200-r4 works better then the 700r4 with inline 6's not as big a ratio diff, between 1st-2nd. just thought i'd add that for consideration.

05-22-2010, 09:58 PM	#8
jablack Classic Chevy Recycler Join Date: Dec 2007 Location: Alabama Posts: 422	Re: 6 cyl Overdrive transmission Does someone make a carb bracket for the detent cable? __________________ 2004 Chevrolet Trailblazer EXT 1970 Chevrolet C50 1979 Chevrolet C30 Need another 67 or 68 soon...

05-30-2010, 02:45 AM	#9
raycow Registered User Join Date: Mar 2003 Location: San Francisco, CA USA Posts: 2,454	Re: 6 cyl Overdrive transmission I haven't seen an aftermarket bracket for the 6, but you can adapt the stock bracket used for the TH350 cable. Ray

05-30-2010, 07:46 AM	#10
PanelDeland I am a Referee of life. Join Date: Jun 2000 Location: Greensboro N.C. Posts: 13,993	Re: 6 cyl Overdrive transmission You will also have to check Driveshaft length,crossmember placement(or get one if yours is manual now)and steering column or shifter will need to be adressed.You will also have to remove the existing crossmember if yours is manual. __________________ The 47-present Chevrolet and GMC Truck Message Board Network,it's owners,moderators,members,and associates of any type should not be held responsible for my opinion. You can't fix stupid,not even with duct tape. "My appearance is due to the fact that "GOD" does punish you for having too much fun!" Barrett-Jackson has perfected alchemy,they make rust into gold! "You can lead a horse to water but you can't saddle a duck" "Cleverly disguised as a 'Responsible Adult' "Sometimes your Knight in shining armor is just a retard in tinfoil"

05-30-2010, 10:05 AM	#11
69_hafton Sleep-Deprived Join Date: Sep 2002 Location: Tulsa, Oklahoma Posts: 445	Re: 6 cyl Overdrive transmission Just to give you a ballpark number to look for, I'm under the impression from past info gathering that a 3.73 gearing set-up is what you're looking for in the diff. I've got a 4.10 and can comfortably go 65 with the overdrive (I think it's a .73?), but much more than that and the rpm's get uncomfortable. There are probably other ratios that can be used, but they aren't as common, but maybe for more top end you could find around a 3.54? __________________ 1971 K/10 Long Fleetside 350/350 - 6" Lift 1969 C/10 SWB 292 - Sold It

05-30-2010, 03:05 PM	#12
Jacfourteen Big Red - Now its a SWB! Join Date: Jun 2009 Location: Oroville, Ca Posts: 1,624	Re: 6 cyl Overdrive transmission I thought most of the I6's were geared low (4.10-4.56, or is that with the Manual?) so they should still have decent highway rpms even with OD. Anyways the rear gear is def an important consideration. I've heard that you can find OD trannies with the same overall length so the driveshaft won't have to be modified. I think you can use the same crossmember, but you have to move it back a few inches and redrill the mounting holes in the frame. Other than that it will be a pretty easy swap. __________________ 68 3/4 ton (Project)-350 Small Block, .030 over, 10:1 comp, 3998993 heads, C3BX edelbrock intake, comp cams XE268, Holley 670 SA, long tube headers, dual flow 40's, E-fan, Alum rad, currently under the knife getting shortened and bagged build thread 41 3/4 ton (wife's)-flatbed, fully restored to original 01 Tahoe LT 4WD (my daily driver)-Magnaflow Muffler, Rollin on 22's 02 Ford Mustang Convertable (Wife's Car)-Flowmaster 50, Clear corners, Intake, sittin on 18's

02-23-2011, 11:35 PM	#13
72gmcer Registered User Join Date: Dec 2010 Location: Pasadena, Tx Posts: 29	Re: 6 cyl Overdrive transmission I was planning on putting a 700r4 behind my 250 also. Converting from a manual three speed. Does anyone know of a build thread that touches alittle more on the subject with maybe some pics. I'm new to the site and just want to say that this is the most informative site I've ever visited. Posted via Mobile Device

03-08-2016, 06:46 PM	#14
jhyder408 Registered User Join Date: Oct 2007 Location: Albany, OR Posts: 93	Re: 6 cyl Overdrive transmission ist an old thread but I'm looking doing this... anymore input would be great. not necessarily concerned with gears but overall setup, manual to 700r4 in short box with a 250 6cyl __________________ '68 C10 Step Side, 250 6cyl, converted long to short, work in progress

03-08-2016, 07:49 PM	#15
Jurassic-1 Registered User Join Date: Jul 2007 Location: New River Arizona Posts: 1,180	Re: 6 cyl Overdrive transmission I was going to do the same thing on my 1966 truck. I have a 200r4 and asked Bowtie overdrives about the detent. He said there is not enough call for it and because the linkage is backwards it is more difficult to do. It can be done but the geometry should be on to not damage the transmission. I would also be interested if any one has install tips.

03-08-2016, 09:15 PM	#16
arkansas Registered User Join Date: Jan 2008 Location: Pleasant Plains, Arkansas Posts: 51	Re: 6 cyl Overdrive transmission I'm in the process of putting a 2004r behind a 250 in my 71. It originally had a factory T350 behind the 250 (odd combo but it's on the original spid). The 200 is the same length as a t350 so the driveshaft length is fine. The bell housing to mount location matches a t400 so you only have to move the stock crossmember to the t400 bolt holes in the frame so no drilling. Mine is all bolted in now but I've not tackled the cable yet. Still saving for FI for it first. The inlines were pretty torquey at low revs so I'm not too concerned about 3.73 being too high rear. Just pull it out if OD in town. I do that now in a Chevy coupe I'm running a 700r4 in behind a small block with 3.73 rear.



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