muncie 4 speed?? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

ingie · 06-20-2003, 09:58 PM

i was wondering if some one could help me out ? will a muncie 4 speed bolt up to my 67 c10 which has a 250 six in it???

*racedvl* · 06-20-2003, 10:21 PM

What kind of munce 4 speed?

**'68OrangeSunshine** · 06-21-2003, 03:54 AM

The '67 model year used the Muncie SM (synchromesh) 420 4-speed transmission. The '68 and later (to '87 maybe?) use the Muncie SM 465. The 420 was shorter than the 465 and had lower intermediate gear ratios. They have been considered a real good swap for other-make off roaders, [Jeeps, Toyos, IHs etc] and so may now be hard to find. 420s had a different shift pattern than the 465: while the 4 gears were in the standard "H" pattern, I think the 420's reverse was left of 1st and up, while the 465 goes into reverse off right of 4th and down. That's one way to tell them apart in a junkyard.
I don't know if the number of splines in the tailshaft was the same or different.
A SM 465 could be made to fit in a '67 but not without modifying either the driveline length or the engine mounting position. I don't think it's a simple bolt-in.
The good news is that the same bellhousing is used for both the L6 engines and big and small block V8s.
Hope this helps.

highboy_04 · 06-21-2003, 04:35 PM

the muncie sm420 had reverse toward you and down........i got one in my 67. Steve

ZOOMY · 06-21-2003, 09:18 PM

The car muncies will bolt right up. You'll need a floorshift though, preferably a Hurst. The muncie shifter were junk right from the factory. (my opinion only).

**'68OrangeSunshine** · 06-22-2003, 04:26 AM

OK, thanks, Steve. I never really got a good look at a real 420 outside the '67 Chassis manual, my '68 stepside and '71 Jimmy both have 465s which I'm used to.
How early did this tranny series go? What early years should our buddy here be looking for to find a core 420?

highboy_04 · 06-22-2003, 05:47 PM

i think that the sm 420 went from like 1947 to 1967 im not too sure it might have gone earlier. Steve

highboy_04 · 06-22-2003, 05:49 PM

i'll sell him mine if he wants it. i'm gonna go for a turbo 350 probably since i dont pull alot of stuff i dont need the low first gear. Steve

06-20-2003, 09:58 PM	#1
ingie Registered User Join Date: May 2003 Location: saskatchewan,canada Posts: 7	muncie 4 speed?? i was wondering if some one could help me out ? will a muncie 4 speed bolt up to my 67 c10 which has a 250 six in it???

06-21-2003, 03:54 AM	#3
'68OrangeSunshine Senior Member Join Date: Feb 2002 Location: Tucson, AZ USA Posts: 7,622	The '67 model year used the Muncie SM (synchromesh) 420 4-speed transmission. The '68 and later (to '87 maybe?) use the Muncie SM 465. The 420 was shorter than the 465 and had lower intermediate gear ratios. They have been considered a real good swap for other-make off roaders, [Jeeps, Toyos, IHs etc] and so may now be hard to find. 420s had a different shift pattern than the 465: while the 4 gears were in the standard "H" pattern, I think the 420's reverse was left of 1st and up, while the 465 goes into reverse off right of 4th and down. That's one way to tell them apart in a junkyard. I don't know if the number of splines in the tailshaft was the same or different. A SM 465 could be made to fit in a '67 but not without modifying either the driveline length or the engine mounting position. I don't think it's a simple bolt-in. The good news is that the same bellhousing is used for both the L6 engines and big and small block V8s. Hope this helps. __________________ Every 25 years I like to rebuild that 292, whether it needs it or not.

06-21-2003, 04:35 PM	#4
highboy_04 Registered User Join Date: Mar 2003 Location: kansas Posts: 1,071	the muncie sm420 had reverse toward you and down........i got one in my 67. Steve __________________ '67 c10 350/th350

06-21-2003, 09:18 PM	#5
ZOOMY Senior Member Join Date: Feb 2003 Location: WIS Posts: 1,752	car muncie The car muncies will bolt right up. You'll need a floorshift though, preferably a Hurst. The muncie shifter were junk right from the factory. (my opinion only).

06-22-2003, 05:47 PM	#7
highboy_04 Registered User Join Date: Mar 2003 Location: kansas Posts: 1,071	i think that the sm 420 went from like 1947 to 1967 im not too sure it might have gone earlier. Steve __________________ '67 c10 350/th350

06-20-2003, 10:21 PM	#2
racedvl Account Suspended Join Date: Jan 2000 Location: Woodstock, IL Posts: 7,020	What kind of munce 4 speed?

06-22-2003, 04:26 AM	#6
'68OrangeSunshine Senior Member Join Date: Feb 2002 Location: Tucson, AZ USA Posts: 7,622	OK, thanks, Steve. I never really got a good look at a real 420 outside the '67 Chassis manual, my '68 stepside and '71 Jimmy both have 465s which I'm used to. How early did this tranny series go? What early years should our buddy here be looking for to find a core 420?

06-22-2003, 05:49 PM	#8
highboy_04 Registered User Join Date: Mar 2003 Location: kansas Posts: 1,071	i'll sell him mine if he wants it. i'm gonna go for a turbo 350 probably since i dont pull alot of stuff i dont need the low first gear. Steve __________________ '67 c10 350/th350



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