tranny swap question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

kdevore2 · 02-02-2007, 08:28 AM

I have a 350/350 combo in my 66 SWB. Want to put in a 700r4 but use my existing driveshaft. Is it possible to move the motor mounts forward on the frame to compensate for the extra length of the 700r4 and still be able to use my old driveshaft? Is this more trouble/money than just having a custom driveshaft made. Don't really want to cut my original down, no one around here that actually balances it. They just cut it on a lathe and weld it back together. Others have told me the results are not always that good.

bowtieguy61 · 02-02-2007, 09:18 AM

i was under the impression that a long shaft th350 was the same length as a 700r4.

kdevore2 · 02-02-2007, 09:50 AM

Mines a short shaft I believe.

65 on 24's · 02-02-2007, 10:35 AM

i got a 700r and my drive shaft fit right in . how long is your tranny mine is 32in

**Chevy Fleetside** · 02-02-2007, 11:06 AM

Quote:

Originally Posted by 65 on 24's

i got a 700r and my drive shaft fit right in . how long is your tranny mine is 32in

This would be a long shaft 350.. I believe the short shaft is 28".. When I redid my truck I put a long shaft TH350 in it and when I switched to a 700R4 the shaft was perfect... You will have to get your shaft shortened or maybe you can find one out of another truck or van but measure for it first.. I think the ones out of vans will work and the only reason I never used one is at the yards they are all bent from idiots using fork lifts... Measure one out of a van.. I did this 5 years ago so I am a bit foggy on it..

bowtieguy61 · 02-02-2007, 01:14 PM

if your 350 is a short shaft , you would have to move the motor way to far forward. unfortunately a shorter shaft is the solution. there would have to be somewhere around there that does driveshafts. a new 1-piece shaft isnt expensive. the last time i bought one it was around $125. if you have a 4x4 place around there, they would know who does drive shafts.

krue · 02-02-2007, 01:34 PM

Another option is to use a 200-4r tranny, which will fit right in place of your short shaft 350.

04Xrider · 02-02-2007, 04:09 PM

Around here, they charge $60.00 to shorten, balance, and paint a driveshaft. Seems pretty reasonable.

kdevore2 · 02-02-2007, 06:28 PM

Quote:

Originally Posted by krue

Another option is to use a 200-4r tranny, which will fit right in place of your short shaft 350.

Does the crossmember tranny mount have to be modified for the 200-4r?

krue · 02-03-2007, 12:07 AM

You just have to slide it back, you can bolt the mount from your th-350 to the back of the 200 and slide the crossmember back until the mount is lined up with it, then drill the holes in the frame to mount it. I had one I bought from a jy in mine, but it wouldn't shift out so I took it back out. With a kit for the TV cable and wiring (bowtie overdrive sells tlhem www.2004r.com) you'll be good to go.

02-02-2007, 08:28 AM	#1
kdevore2 Registered User Join Date: Sep 2006 Location: Centralia, IL Posts: 27	tranny swap question I have a 350/350 combo in my 66 SWB. Want to put in a 700r4 but use my existing driveshaft. Is it possible to move the motor mounts forward on the frame to compensate for the extra length of the 700r4 and still be able to use my old driveshaft? Is this more trouble/money than just having a custom driveshaft made. Don't really want to cut my original down, no one around here that actually balances it. They just cut it on a lathe and weld it back together. Others have told me the results are not always that good.

02-02-2007, 09:18 AM	#2
bowtieguy61 Registered User Join Date: Jan 2007 Location: indiana Posts: 52	Re: tranny swap question i was under the impression that a long shaft th350 was the same length as a 700r4.

02-02-2007, 09:50 AM	#3
kdevore2 Registered User Join Date: Sep 2006 Location: Centralia, IL Posts: 27	Re: tranny swap question Mines a short shaft I believe.

02-02-2007, 10:35 AM	#4
65 on 24's Registered User Join Date: Sep 2006 Location: memphis tn, (nutbush) Posts: 160	Re: tranny swap question i got a 700r and my drive shaft fit right in . how long is your tranny mine is 32in __________________ ridin big yo 5in cpp lowerin springs in back lowered 3in in front with cut springs for now 5 lug swap and disk in front 5 lug and disk in the rear with 3.23 gears mild 350/400heads 7547weiand intake 600 Edelbrock chrome block hugger headers 2 1/2 pipes in to a x pipes super 40 flows and turn downs turbo 350 with shift kit

02-02-2007, 01:14 PM	#6
bowtieguy61 Registered User Join Date: Jan 2007 Location: indiana Posts: 52	Re: tranny swap question if your 350 is a short shaft , you would have to move the motor way to far forward. unfortunately a shorter shaft is the solution. there would have to be somewhere around there that does driveshafts. a new 1-piece shaft isnt expensive. the last time i bought one it was around $125. if you have a 4x4 place around there, they would know who does drive shafts.

02-02-2007, 01:34 PM	#7
krue Designated A-hole! Join Date: Mar 2003 Location: South Mississippi Posts: 36,448	Re: tranny swap question Another option is to use a 200-4r tranny, which will fit right in place of your short shaft 350. __________________ "If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck"

02-02-2007, 04:09 PM	#8
04Xrider Registered thread killer Join Date: Nov 2006 Location: Cookson, OK. Posts: 349	Re: tranny swap question Around here, they charge $60.00 to shorten, balance, and paint a driveshaft. Seems pretty reasonable.

02-03-2007, 12:07 AM	#10
krue Designated A-hole! Join Date: Mar 2003 Location: South Mississippi Posts: 36,448	Re: tranny swap question You just have to slide it back, you can bolt the mount from your th-350 to the back of the 200 and slide the crossmember back until the mount is lined up with it, then drill the holes in the frame to mount it. I had one I bought from a jy in mine, but it wouldn't shift out so I took it back out. With a kit for the TV cable and wiring (bowtie overdrive sells tlhem www.2004r.com) you'll be good to go. __________________ "If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck"



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