4 spd direct replacement for 3 speed? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

67 C-10 LWB · 06-11-2003, 06:15 PM

I've got a 67 lwb in case the screen didn't clue you in

that has a saginaw 3 speed on the column. I can get a close ratio 4 speed, pretty sure it's a muncy, not sure what it's out of. will this be a direct bolt in? well I am pretty sure it bolts right up to the bell housing, I guess the better question is, is it the same length as the 3 speed? or will my drive shaft have to be shortened? Any info on this will be helpful. Especially from those of you who have made a swap like this. Thanks

Ean

MandarinSixSeven · 06-11-2003, 07:01 PM

I made the swap from a saginaw 3-speed to a saginaw 4-speed, and that was an absolute direct bolt in. A muncie on the other hand, from what I have read, has more teeth on the input shaft so you would need a different clutch. The ouput shaft im unsure of, and the length I dont know either. Find out for sure if its a muncie or a sag. You can tell by looking at the side plate: if the reverse lever is on the side plate its a saginaw, if its on the tail shaft its a muncie...hope that helps

MandarinSixSeven · 06-11-2003, 07:02 PM

Saginaws have 10 teeth on the input shaft by the way...muncies are either 22 or 26 i believe depending on weather it is an M-20/21 or M-22

67 C-10 LWB · 06-11-2003, 07:06 PM

cool, thanks for the info.
Hopefully I'll be checking it out this Friday, my fiance's dad is the one w/ it and he can't remember, it's from his dirt tracking racing days. Thanks again

Ean

crazy longhorn · 06-11-2003, 08:00 PM

The M 20/21/22 are the same lenght as a saginaw trans. The M 22 should be a 1 1/8x26 spline input shaft, with a 30 spline output shaft(same as a 400 turbo). i wont say all, but most of the passenger M 20/21s had a 1 1/8x 10 spline input, & same out put spline as a saginaw, or a 350 turbo(27 spline i beleive). 67 & earlier truck bell has the proper centerhole for the Muncie trans(4.683,same as the car). The 68 up truck bells have a 5.126 center hole......if you run into this, you can swap the bell, or have a ring machined to press over the front bearing retainer on the muncie to give the proper pilot. The bottom 2 bolts on the trans will be a bolt & nut deal, as the truck bell is not threaded(no problem tho). Good luck,crazyL

06-11-2003, 06:15 PM	#1
67 C-10 LWB Registered User Join Date: Nov 2000 Location: Bay City, MI, USA Posts: 452	4 spd direct replacement for 3 speed? I've got a 67 lwb in case the screen didn't clue you in that has a saginaw 3 speed on the column. I can get a close ratio 4 speed, pretty sure it's a muncy, not sure what it's out of. will this be a direct bolt in? well I am pretty sure it bolts right up to the bell housing, I guess the better question is, is it the same length as the 3 speed? or will my drive shaft have to be shortened? Any info on this will be helpful. Especially from those of you who have made a swap like this. Thanks Ean __________________ 1999 Silverado Ext Cab Short Box Z71 2006 Trailblazer (wifes) 2 '04 KFX400's My Site

06-11-2003, 07:01 PM	#2
MandarinSixSeven Seasonal Poster Join Date: Apr 2002 Location: Kelowna BC Canada Posts: 896	I made the swap from a saginaw 3-speed to a saginaw 4-speed, and that was an absolute direct bolt in. A muncie on the other hand, from what I have read, has more teeth on the input shaft so you would need a different clutch. The ouput shaft im unsure of, and the length I dont know either. Find out for sure if its a muncie or a sag. You can tell by looking at the side plate: if the reverse lever is on the side plate its a saginaw, if its on the tail shaft its a muncie...hope that helps __________________ 67 GMC Short Step 350/4-Speed/3.08 Posi Front/Rear Sway Bars Kelowna BC, Canada Member of DTPW

06-11-2003, 07:02 PM	#3
MandarinSixSeven Seasonal Poster Join Date: Apr 2002 Location: Kelowna BC Canada Posts: 896	Saginaws have 10 teeth on the input shaft by the way...muncies are either 22 or 26 i believe depending on weather it is an M-20/21 or M-22 __________________ 67 GMC Short Step 350/4-Speed/3.08 Posi Front/Rear Sway Bars Kelowna BC, Canada Member of DTPW

06-11-2003, 07:06 PM	#4
67 C-10 LWB Registered User Join Date: Nov 2000 Location: Bay City, MI, USA Posts: 452	cool, thanks for the info. Hopefully I'll be checking it out this Friday, my fiance's dad is the one w/ it and he can't remember, it's from his dirt tracking racing days. Thanks again Ean __________________ 1999 Silverado Ext Cab Short Box Z71 2006 Trailblazer (wifes) 2 '04 KFX400's My Site

06-11-2003, 08:00 PM	#5
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,403	The M 20/21/22 are the same lenght as a saginaw trans. The M 22 should be a 1 1/8x26 spline input shaft, with a 30 spline output shaft(same as a 400 turbo). i wont say all, but most of the passenger M 20/21s had a 1 1/8x 10 spline input, & same out put spline as a saginaw, or a 350 turbo(27 spline i beleive). 67 & earlier truck bell has the proper centerhole for the Muncie trans(4.683,same as the car). The 68 up truck bells have a 5.126 center hole......if you run into this, you can swap the bell, or have a ring machined to press over the front bearing retainer on the muncie to give the proper pilot. The bottom 2 bolts on the trans will be a bolt & nut deal, as the truck bell is not threaded(no problem tho). Good 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....



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