overdrive? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Frankd · 12-06-2003, 09:52 AM

I have an81 C-30 dually gonna use it to pull my 72 on trailer to car shows. wanna put in an overdrive, it now has the granny gear 4spd9not real good at highway speeds)will a newer 5 speed bolt up or an overdrive ubit? it has a 350 motor

Mike76251 · 12-06-2003, 10:49 AM

I tow with a 700R4 but would not recommend them for that as they have a bad history (without expensive upgrades)
You might look into a outboard overdrive like the one Advance Adaptors makes........they are kinda high but can handle nearly any torque level you can put through them.

*1FaastC10* · 12-06-2003, 07:10 PM

wouldnt a 5 speed out of a newer truck work? isnt the NV 4500 a strong OD trans?

PHOENIX · 12-08-2003, 01:45 PM

Like FaastC10 stated you could use a NV4500, it has a low first gear like you have now, and it adds the overdrive. Not sure what you would have to mod, but I am sure it would be a pretty straight forward swap. I am sure the clutch, bell housing and all would work but you may need to change the clutch disc if the tooth count is different. May need to cut drive shaft, move crossmember, and maybe cut new shifter hole.
Here is a good link:
http://www.motivegear.com/tech_info/...nny_guide.html

I am trying to get one of these for my C10 (1386-000-011MS):
http://www.standardtransmission.com/BW_T-56.html

12-06-2003, 09:52 AM	#1
Frankd Registered User Join Date: Nov 2003 Location: Mauk, Ga Posts: 76	overdrive? I have an81 C-30 dually gonna use it to pull my 72 on trailer to car shows. wanna put in an overdrive, it now has the granny gear 4spd9not real good at highway speeds)will a newer 5 speed bolt up or an overdrive ubit? it has a 350 motor

12-08-2003, 01:45 PM	#4
PHOENIX Registered User Join Date: Oct 2002 Location: Phoenix, Arizona Posts: 4,703	Like FaastC10 stated you could use a NV4500, it has a low first gear like you have now, and it adds the overdrive. Not sure what you would have to mod, but I am sure it would be a pretty straight forward swap. I am sure the clutch, bell housing and all would work but you may need to change the clutch disc if the tooth count is different. May need to cut drive shaft, move crossmember, and maybe cut new shifter hole. Here is a good link: http://www.motivegear.com/tech_info/...nny_guide.html I am trying to get one of these for my C10 (1386-000-011MS): http://www.standardtransmission.com/BW_T-56.html __________________ * AVOID: LOPER'S PERMORANCE / LOPERSPEED.COM OF PHOENIX, AZ & COTTMAN TRANSMISSION *

12-06-2003, 10:49 AM	#2
Mike76251 Senior Member Join Date: Mar 2003 Posts: 2,500	I tow with a 700R4 but would not recommend them for that as they have a bad history (without expensive upgrades) You might look into a outboard overdrive like the one Advance Adaptors makes........they are kinda high but can handle nearly any torque level you can put through them.

12-06-2003, 07:10 PM	#3
1FaastC10 Account Suspended Join Date: Oct 2002 Location: Elkhart, IN Posts: 6,400	wouldnt a 5 speed out of a newer truck work? isnt the NV 4500 a strong OD trans?



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