700R4 question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

67pro-street · 12-28-2004, 12:21 AM

I am installing a 700r4 tranny in my truck. It is taking place of the original 4 spd manual tranny. my engine and tranny were originally in the I-6 position and are now moved to the 350 position. I was wondering if anybody else out there who has done this conversion would know how much i need to shorten my drive shaft for the new tranny. I also have a 4/6 drop on the truck. If no one knows that, could any one tell me how far out the yoke comes from the tailshaft on a 27 spline transmission. That way i could compensate for the yoke and take my measurements myself. Thanks in advance,

67pro-street.

BobbyK · 12-28-2004, 02:11 AM

Well when I installed my 700R4 into my Blazer.I moved the eng forward and just redrilled a couple holes.This meant I could retain the tranfer case mounting position and keep my front and rear drive shafts at stock length.

I moved my eng towards the rad approx 1"7/8" from the standard V8 location

Tx Firefighter · 12-28-2004, 09:45 AM

I converted a 6 cylinder truck to V8 and 700r4. The original driveshaft on the truck was a 1 piece shaft.

By the time I moved the engine forward and put the V8 frame stands in and then the 700R4 being longer, the stock driveshaft worked perfectly. No mods needed. Mine was an origianl 3 speed truck too by the way.

crazy longhorn · 12-28-2004, 06:09 PM

Slide the slip yolk into the trans till it bottoms....then pull it back out 3/4" minimum, to 1" max , & then you can measure c to c on the shaft. im not sure if you have a short or long wb truck, but if you are under 70 or 71 " c to c on the caps, I would look at a 1 pc shaft. best of luck,crazyL

67ChevyRedneck · 12-28-2004, 06:27 PM

I have a 1 piece shaft, 67 swb, that was an I6 3sp converted to a 350 700R4 in the stock V8 location and I think I had to shorten my shaft about 5 inches or so. I don't know a lot about the 3 speeds, but the 3 sp in my dad's 69 was a lot longer than the 3 sp in my 67. I was told GM made two different 3 speeds, one with a long tail and one with a short?? I measured mine like crazy_longhorn said and took it to a machine shop.

67pro-street · 12-28-2004, 07:20 PM

thanks for the help guys. i do have a long wheel base truck and i am pretty sure that the original tranny was a short tailshaft. will this make a differnce. once again, thanks for the help

67pro-street

**guyryan100** · 12-28-2004, 10:22 PM

To be safe, just wait till the tranny is in and you can measure it out right. I did the swap, had a 3spd manual before, and had to cut the shaft about 2" for the 700r4. I'm told that the 700r4 may have a different length based on the donor vehicle.

BobM · 12-29-2004, 09:00 PM

I did this conversion with my 71 Fleetside LWB. Used the original two piece drive shaft with out any modification. Turned out that the 700R4 tail shaft was about 1/2 inch further forward than the three speed manual, so wasn't a problem. Engine is in the V8 position. 700R4 is out of a 87 Pontiac.

12-28-2004, 12:21 AM	#1
67pro-street Registered User Join Date: Jan 2003 Location: Bellingham, WA Posts: 218	700R4 question I am installing a 700r4 tranny in my truck. It is taking place of the original 4 spd manual tranny. my engine and tranny were originally in the I-6 position and are now moved to the 350 position. I was wondering if anybody else out there who has done this conversion would know how much i need to shorten my drive shaft for the new tranny. I also have a 4/6 drop on the truck. If no one knows that, could any one tell me how far out the yoke comes from the tailshaft on a 27 spline transmission. That way i could compensate for the yoke and take my measurements myself. Thanks in advance, 67pro-street.

12-28-2004, 02:11 AM	#2
BobbyK Registered User Join Date: May 2000 Location: Petrolia,Ontario,Canada but working in Port Huron,Mi. Posts: 1,771	Well when I installed my 700R4 into my Blazer.I moved the eng forward and just redrilled a couple holes.This meant I could retain the tranfer case mounting position and keep my front and rear drive shafts at stock length. I moved my eng towards the rad approx 1"7/8" from the standard V8 location __________________ 71 blazer,350SBC,approx.375HP,700R4,factory GM TPI.Dual electric fans,33x12.5x15 ATR on stock suspension. Petrolia,Ontario,Canada but working in Port Huron,MI. See ALL my Blazer pic's HERE

12-28-2004, 09:45 AM	#3
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	I converted a 6 cylinder truck to V8 and 700r4. The original driveshaft on the truck was a 1 piece shaft. By the time I moved the engine forward and put the V8 frame stands in and then the 700R4 being longer, the stock driveshaft worked perfectly. No mods needed. Mine was an origianl 3 speed truck too by the way. __________________ I'm on the Instagram- @Gearhead_Kevin

12-28-2004, 06:09 PM	#4
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,403	Slide the slip yolk into the trans till it bottoms....then pull it back out 3/4" minimum, to 1" max , & then you can measure c to c on the shaft. im not sure if you have a short or long wb truck, but if you are under 70 or 71 " c to c on the caps, I would look at a 1 pc shaft. best of luck,crazyL __________________ 69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....

12-28-2004, 06:27 PM	#5
67ChevyRedneck Hittin E-Z Street on Mud Tires Join Date: Nov 2004 Location: Greenville, SC Posts: 23,090	I have a 1 piece shaft, 67 swb, that was an I6 3sp converted to a 350 700R4 in the stock V8 location and I think I had to shorten my shaft about 5 inches or so. I don't know a lot about the 3 speeds, but the 3 sp in my dad's 69 was a lot longer than the 3 sp in my 67. I was told GM made two different 3 speeds, one with a long tail and one with a short?? I measured mine like crazy_longhorn said and took it to a machine shop. __________________ 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!

12-28-2004, 07:20 PM	#6
67pro-street Registered User Join Date: Jan 2003 Location: Bellingham, WA Posts: 218	thanks for the help guys. i do have a long wheel base truck and i am pretty sure that the original tranny was a short tailshaft. will this make a differnce. once again, thanks for the help 67pro-street

12-28-2004, 10:22 PM	#7
guyryan100 Registered User Join Date: Sep 2001 Location: Cumming, GA Posts: 470	To be safe, just wait till the tranny is in and you can measure it out right. I did the swap, had a 3spd manual before, and had to cut the shaft about 2" for the 700r4. I'm told that the 700r4 may have a different length based on the donor vehicle.

12-29-2004, 09:00 PM	#8
BobM Registered User Join Date: Feb 2001 Location: Winnipeg, MB, Canada Posts: 73	I did this conversion with my 71 Fleetside LWB. Used the original two piece drive shaft with out any modification. Turned out that the 700R4 tail shaft was about 1/2 inch further forward than the three speed manual, so wasn't a problem. Engine is in the V8 position. 700R4 is out of a 87 Pontiac.



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.