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

kev93 · 06-23-2009, 09:33 AM

What 4 speed was used in 1977 1/2 2wd Chevy trucks? Would it be a good performance transmission??

swb85 · 06-23-2009, 09:39 AM

Most likely it's a sm465. Not at all a performance oriented trans with it's granny low gear, definitely a big truck tranny.

kev93 · 06-23-2009, 10:37 AM

Anyone know where I can get the parts to convert my auto to muncie 4 speed.

smashingchuck · 06-23-2009, 10:58 AM

The linkage for the clutch is all the same, and Hurst makes a shifter for the "muncie in a truck". Other than that you'll need a slightly longer drive shaft yoke or you'll need to lengthen the drive shaft about an inch. Use the donor vehicle info when ordering the flywheel, clutch, etc.

*edit*
Hit the junkyard for the pedals and z-bar. I forgot you said you were starting with an auto. Also when I did mine I got the clutch rod boot, springs, new pedal covers, new pedal bushings and all the other small stuff from the dealer.

swb85 · 06-23-2009, 12:16 PM

You cannot lengthen a drive shaft, only shorten it. If the one you have is too short after the conversion, you need a new longer one. Depending on what auto you have now, the stock one should work. I think mine is a stock one piece DS from a th350 2wd truck. I've got a M21 muncie in mine. The stock crossmember can be reused, just drill new holes in the frame. Like said above, find a donor truck in the salvage yard and take EVERYTHING. Pretty easy swap once you have all the parts.

kev93 · 06-23-2009, 12:33 PM

I have the TH350 in mine at the moment.

smashingchuck · 06-23-2009, 11:09 PM

Quote:

Originally Posted by kev93

I have the TH350 in mine at the moment.

That's what my truck had as well. I just went with a yoke that was about 1-1/2 inches longer.

79Silv4x4 · 06-24-2009, 12:34 AM

Quote:

Originally Posted by swb85

You cannot lengthen a drive shaft

Curious to why? ? ?

swb85 · 06-24-2009, 09:37 AM

I should rephrase.......The only way to add length to a drive shaft is to "re-tube" it, meaning you remove both weld yokes and install them on a new tube of the proper length. As cheap as new drive shafts are it's easier/cheaper to just measure and buy a new one.

dan76 · 06-23-2009, 12:41 PM

Depending on what you mean by "performance".......If you're going to power shift, I'd suggest getting a Muncie 4-speed. You can get the mechanical clutch linkage from the wrecking yard or go to LMC and get most of the parts new.

A T-56 is also a reasonable "performance" transmission. From the two I've seen in pickups, you'll have to change the trans mount, possibly modify the crossmember, change shifter location, modify the driveshaft and install a hydraulic clutch setup.

06-23-2009, 09:33 AM	#1
kev93 Registered User Join Date: Jun 2009 Location: Des moines, Iowa Posts: 17	4 speed question What 4 speed was used in 1977 1/2 2wd Chevy trucks? Would it be a good performance transmission??

06-23-2009, 09:39 AM	#2
swb85 On a budget like Fred Sanford Join Date: Oct 2005 Location: Topeka, KS Posts: 2,031	Re: 4 speed question Most likely it's a sm465. Not at all a performance oriented trans with it's granny low gear, definitely a big truck tranny. __________________ '85 Silverado swb: 383 stroker, 10.5:1, vortec heads, 232/238 roller cam, RPM air gap, performer 750 carb, stainless longtubes, 3" duals/super 44's, T56/4.11 383ci build / exterior refresh thread '98 Camaro z28: 370ci twin turbo 370ci build '01 Tahoe LT 4x4: 5.3, longtubes/ory, magnaflow duals, custom tune....wife's DD

06-23-2009, 10:37 AM	#3
kev93 Registered User Join Date: Jun 2009 Location: Des moines, Iowa Posts: 17	Re: 4 speed question Anyone know where I can get the parts to convert my auto to muncie 4 speed.

06-23-2009, 10:58 AM	#4
smashingchuck It'd be alot cooler if you did Join Date: May 2003 Location: Three Rivers, MI Posts: 2,345	Re: 4 speed question The linkage for the clutch is all the same, and Hurst makes a shifter for the "muncie in a truck". Other than that you'll need a slightly longer drive shaft yoke or you'll need to lengthen the drive shaft about an inch. Use the donor vehicle info when ordering the flywheel, clutch, etc. edit Hit the junkyard for the pedals and z-bar. I forgot you said you were starting with an auto. Also when I did mine I got the clutch rod boot, springs, new pedal covers, new pedal bushings and all the other small stuff from the dealer. __________________ 78 Build Thread 4Runner Build Last edited by smashingchuck; 06-23-2009 at 11:00 AM.

06-23-2009, 12:16 PM	#5
swb85 On a budget like Fred Sanford Join Date: Oct 2005 Location: Topeka, KS Posts: 2,031	Re: 4 speed question You cannot lengthen a drive shaft, only shorten it. If the one you have is too short after the conversion, you need a new longer one. Depending on what auto you have now, the stock one should work. I think mine is a stock one piece DS from a th350 2wd truck. I've got a M21 muncie in mine. The stock crossmember can be reused, just drill new holes in the frame. Like said above, find a donor truck in the salvage yard and take EVERYTHING. Pretty easy swap once you have all the parts. __________________ '85 Silverado swb: 383 stroker, 10.5:1, vortec heads, 232/238 roller cam, RPM air gap, performer 750 carb, stainless longtubes, 3" duals/super 44's, T56/4.11 383ci build / exterior refresh thread '98 Camaro z28: 370ci twin turbo 370ci build '01 Tahoe LT 4x4: 5.3, longtubes/ory, magnaflow duals, custom tune....wife's DD

06-23-2009, 12:33 PM	#6
kev93 Registered User Join Date: Jun 2009 Location: Des moines, Iowa Posts: 17	Re: 4 speed question I have the TH350 in mine at the moment.

06-24-2009, 09:37 AM	#9
swb85 On a budget like Fred Sanford Join Date: Oct 2005 Location: Topeka, KS Posts: 2,031	Re: 4 speed question I should rephrase.......The only way to add length to a drive shaft is to "re-tube" it, meaning you remove both weld yokes and install them on a new tube of the proper length. As cheap as new drive shafts are it's easier/cheaper to just measure and buy a new one. __________________ '85 Silverado swb: 383 stroker, 10.5:1, vortec heads, 232/238 roller cam, RPM air gap, performer 750 carb, stainless longtubes, 3" duals/super 44's, T56/4.11 383ci build / exterior refresh thread '98 Camaro z28: 370ci twin turbo 370ci build '01 Tahoe LT 4x4: 5.3, longtubes/ory, magnaflow duals, custom tune....wife's DD

06-23-2009, 12:41 PM	#10
dan76 Registered User Join Date: Mar 2008 Location: Salt Lake City UT Posts: 441	Re: 4 speed question Depending on what you mean by "performance".......If you're going to power shift, I'd suggest getting a Muncie 4-speed. You can get the mechanical clutch linkage from the wrecking yard or go to LMC and get most of the parts new. A T-56 is also a reasonable "performance" transmission. From the two I've seen in pickups, you'll have to change the trans mount, possibly modify the crossmember, change shifter location, modify the driveshaft and install a hydraulic clutch setup.



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