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

RCon · 01-17-2020, 07:48 PM

I have a 72 C20 pickup with a th350. I want to change it to a 700r4 and want to know if anyone knows where i can get the new crossmember for it.

71meangreenc10 · 01-17-2020, 09:30 PM

https://www.partsgeek.com/chpjx2r-ch...on+Crossmember

Worked for me.

Smitty

Andy4639 · 01-18-2020, 11:27 AM

No need for a new crossmember it will work fine on your 350 but you will need the rubber mount for it. That it. I just did a 700-R4 in my 68. Slide the crossmember back and drilled 2 holes.

71meangreenc10 · 01-18-2020, 11:34 AM

Andy,

Post a pic of how it looks to access the rear pan bolts with a stock crossmember.

Smitty

Andy4639 · 01-18-2020, 10:36 PM

I will try and remember to do this tomorrow. From what I remember it's very tight but doable. I used this same setup on the 71 C 10 when I did the 700-R4 in it.

**Smitty** · 01-20-2020, 09:22 AM

When I dis mine I trimmed the small horizontal flange on the front of the crossmember. Then added a plate inside the vertical to strengthen it. Gives needed space for access to rear pan bolts. Although the gusset probably wasn’t necessary. 15+ yrs. no issues.

01-17-2020, 07:48 PM	#1
RCon Registered User Join Date: Jul 2017 Location: East Islip Posts: 1	Transmission swap question I have a 72 C20 pickup with a th350. I want to change it to a 700r4 and want to know if anyone knows where i can get the new crossmember for it.

01-17-2020, 09:30 PM	#2
71meangreenc10 Its a Truck Thing...... Join Date: Dec 2004 Location: Sierra Vista, Arizona Posts: 3,179	Re: Transmission swap question https://www.partsgeek.com/chpjx2r-ch...on+Crossmember Worked for me. Smitty __________________ 71 C10 283/3SPD Full Resto 71 GMC 1500 Sierra Grande http://67-72chevytrucks.com/vboard/s...d.php?t=518599 70 C10 Suburban Former military GSA truck. 72 Chevy Blazer 4X4, Sloppy Jo, Mountain Climber. Wife says no more trucks. http://67-72chevytrucks.com/vboard/s...d.php?t=707378 72 GMC 1 Ton Motor Home, wife said no more trucks until she saw this one. Gen 3 6.0/4L80E 4.10 http://67-72chevytrucks.com/vboard/s...d.php?t=761110 68 GMC Suburban was 3/4 ton, now 1/2.Wife shook her head 71 C30 Wrecker 71 C20 Scott-Bilt As weird as it gets..BB Cheyenne AC Truck 68 GMC Long Stepside. They keep following me home 69 C30 Former Motor Home, Flat Bed time 70 G20 Red-E-Kamp Conversion "I'm your Boogy Van"

01-18-2020, 11:27 AM	#3
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,945	Re: Transmission swap question No need for a new crossmember it will work fine on your 350 but you will need the rubber mount for it. That it. I just did a 700-R4 in my 68. Slide the crossmember back and drilled 2 holes. Attached Images __________________ 1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs.

01-18-2020, 11:34 AM	#4
71meangreenc10 Its a Truck Thing...... Join Date: Dec 2004 Location: Sierra Vista, Arizona Posts: 3,179	Re: Transmission swap question Andy, Post a pic of how it looks to access the rear pan bolts with a stock crossmember. Smitty __________________ 71 C10 283/3SPD Full Resto 71 GMC 1500 Sierra Grande http://67-72chevytrucks.com/vboard/s...d.php?t=518599 70 C10 Suburban Former military GSA truck. 72 Chevy Blazer 4X4, Sloppy Jo, Mountain Climber. Wife says no more trucks. http://67-72chevytrucks.com/vboard/s...d.php?t=707378 72 GMC 1 Ton Motor Home, wife said no more trucks until she saw this one. Gen 3 6.0/4L80E 4.10 http://67-72chevytrucks.com/vboard/s...d.php?t=761110 68 GMC Suburban was 3/4 ton, now 1/2.Wife shook her head 71 C30 Wrecker 71 C20 Scott-Bilt As weird as it gets..BB Cheyenne AC Truck 68 GMC Long Stepside. They keep following me home 69 C30 Former Motor Home, Flat Bed time 70 G20 Red-E-Kamp Conversion "I'm your Boogy Van"

01-18-2020, 10:36 PM	#5
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,945	Re: Transmission swap question I will try and remember to do this tomorrow. From what I remember it's very tight but doable. I used this same setup on the 71 C 10 when I did the 700-R4 in it. __________________ 1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs.

01-20-2020, 09:22 AM	#6
Smitty Senior Member Join Date: Dec 1999 Location: Spring Valley, Ca. Posts: 1,133	Re: Transmission swap question When I dis mine I trimmed the small horizontal flange on the front of the crossmember. Then added a plate inside the vertical to strengthen it. Gives needed space for access to rear pan bolts. Although the gusset probably wasn’t necessary. 15+ yrs. no issues. __________________ Smitty '71 Short Fleetside Spring Valley, Ca.

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