72 GMC pickup 4x4 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

prodjay10 · 04-02-2017, 02:41 AM

Im thinking of converting my 4 on the floor to automatic since I'm going tbi. Would a 700r4 bolt right up?

Bigdav160 · 04-02-2017, 07:45 AM

It's not a terribly hard conversion, meaning your not going to have to fab a lot of parts, but no, it's not a straight bolt in.

If you do a search you'll probably find several threads on issues with the change.

**special-K** · 04-02-2017, 07:55 AM

They are longer than the TH350s that came in them. The transfer case for both automatic and manual are in the same location. You can move the engine towers forward to the 6cyl position and leave the transfer case cross member alone and use the driveshafts as is. Otherwise, you would need to shorten the rear and lengthen the front.

You will need the TH350 adapter used in 70 to late-70s as well. A 700r4 will bolt in an automatic truck with just shifting engine/trans/t-case assembly forward. A 4spd requires sourcing the TH350 adapter. The automatics use a fine spline and the 4spd has a lower count spline. So it's all about the input spline count of the adaptor between 4spd and auto

04-02-2017, 02:41 AM	#1
prodjay10 Registered User Join Date: Jun 2016 Location: Phoenix AZ Posts: 429	72 GMC pickup 4x4 Im thinking of converting my 4 on the floor to automatic since I'm going tbi. Would a 700r4 bolt right up?

04-02-2017, 07:45 AM	#2
Bigdav160 Registered User Join Date: Apr 2011 Location: Klein Texas Posts: 3,852	Re: 72 GMC pickup 4x4 It's not a terribly hard conversion, meaning your not going to have to fab a lot of parts, but no, it's not a straight bolt in. If you do a search you'll probably find several threads on issues with the change. __________________ My Classics: '72 K20 Suburban + '65 Dodge Town Wagon '72 Corvette Roadster +'67 Corvette Roadster '73 Z-28 Camaro '63 Ford SWB Uni Pickup '50 Ford Coupe

04-02-2017, 07:55 AM	#3
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,852	Re: 72 GMC pickup 4x4 They are longer than the TH350s that came in them. The transfer case for both automatic and manual are in the same location. You can move the engine towers forward to the 6cyl position and leave the transfer case cross member alone and use the driveshafts as is. Otherwise, you would need to shorten the rear and lengthen the front. You will need the TH350 adapter used in 70 to late-70s as well. A 700r4 will bolt in an automatic truck with just shifting engine/trans/t-case assembly forward. A 4spd requires sourcing the TH350 adapter. The automatics use a fine spline and the 4spd has a lower count spline. So it's all about the input spline count of the adaptor between 4spd and auto __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~



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