tranny crossmember location - The 1947 - Present Chevrolet & GMC Truck Message Board Network

rodstored-72 · 03-31-2005, 03:17 PM

i am sure that this topic has been covered already, but i am new and would like to know the exact proceedure on how to locate the trans. x-mbr on a 72 2wd p/u for a 700r4 trans. from a short th350?? any help guidance would be greatly appreciated! the knowledge on this site is tremendous (ok enough kissing up!) thanks again for any help..

COBRO · 03-31-2005, 04:23 PM

The th350 will measure 22-1/4" from the face of the bellhousing to the center of the mounting pad and the 700r4 measures 23" so neither of the factory holes will match and you need to drill new ones. HTH:::CB

rodstored-72 · 03-31-2005, 06:56 PM

i hope that's not right, i really don't look foward to doing that. i thought that someone told me that you have to just move the x-mbr back/foward & you would be able to use 2 of the existing holes?? some more input would be nice..

COBRO · 03-31-2005, 07:20 PM

The front holes are for the th-350 and the rear holes are for a th-400,thats the only automatics put in from the factory. So sorry to bring you the bad news.:::::::CB

69 longhorn · 03-31-2005, 08:49 PM

I got this info from the TCI site....from the bell, to the trans mount center on a 350 T is 20 3/8" (6 or 9" tail both the same.) The 700r4 is 22 1/2" from the bell, to the center of the trans mount.....it sounds like you need to drill. Try this site www.tciauto.com

L

rodstored-72 · 04-01-2005, 10:43 AM

thanks all who have commented it is very helpful! now i want to pose another question & that is could somebody who has done it please give me some pointers (proceedures) on how they did the install - as exact as possible would be great!!!

ps: this site rocks!!

**pjmoreland** · 04-01-2005, 12:00 PM

The tailshaft housing on the older 700R4s have a mounting location that is farther back on the housing than the newer 700R4s. This makes it so the crossmember won't block the rear bolts on your pan, and you can use a deep pan without having to trim the front edge of the crossmember.

I'd recommend removing the bolts that attach the crossmember to the chassis. Then install your transmission, and attach the transmission to the crossmember with the two mounting bolts. Make sure the crossmember is sitting perpendicular to and centered on the chassis. You can then mark the new chassis hole locations and drill away. This is way easier if your cab is off. If it's not, it'll be a challenge to drill the upper holes.

03-31-2005, 03:17 PM	#1
rodstored-72 chevy truck fan Join Date: Mar 2005 Location: Gilbert, arizona 85298 Posts: 1,985	tranny crossmember location i am sure that this topic has been covered already, but i am new and would like to know the exact proceedure on how to locate the trans. x-mbr on a 72 2wd p/u for a 700r4 trans. from a short th350?? any help guidance would be greatly appreciated! the knowledge on this site is tremendous (ok enough kissing up!) thanks again for any help..

03-31-2005, 08:49 PM	#5
69 longhorn Registered User Join Date: Aug 2001 Location: rock island,il,usa Posts: 5,382	I got this info from the TCI site....from the bell, to the trans mount center on a 350 T is 20 3/8" (6 or 9" tail both the same.) The 700r4 is 22 1/2" from the bell, to the center of the trans mount.....it sounds like you need to drill. Try this site www.tciauto.com L __________________ http://community.webshots.com/user/hotrodhorn

03-31-2005, 04:23 PM	#2
COBRO Active Member Join Date: Jan 2005 Location: RDM,Oregon Posts: 285	The th350 will measure 22-1/4" from the face of the bellhousing to the center of the mounting pad and the 700r4 measures 23" so neither of the factory holes will match and you need to drill new ones. HTH:::CB

03-31-2005, 06:56 PM	#3
rodstored-72 chevy truck fan Join Date: Mar 2005 Location: Gilbert, arizona 85298 Posts: 1,985	i hope that's not right, i really don't look foward to doing that. i thought that someone told me that you have to just move the x-mbr back/foward & you would be able to use 2 of the existing holes?? some more input would be nice..

03-31-2005, 07:20 PM	#4
COBRO Active Member Join Date: Jan 2005 Location: RDM,Oregon Posts: 285	The front holes are for the th-350 and the rear holes are for a th-400,thats the only automatics put in from the factory. So sorry to bring you the bad news.:::::::CB

04-01-2005, 10:43 AM	#6
rodstored-72 chevy truck fan Join Date: Mar 2005 Location: Gilbert, arizona 85298 Posts: 1,985	thanks all who have commented it is very helpful! now i want to pose another question & that is could somebody who has done it please give me some pointers (proceedures) on how they did the install - as exact as possible would be great!!! ps: this site rocks!!

04-01-2005, 12:00 PM	#7
pjmoreland Senior Member Join Date: Jan 2005 Location: CA Posts: 5,426	The tailshaft housing on the older 700R4s have a mounting location that is farther back on the housing than the newer 700R4s. This makes it so the crossmember won't block the rear bolts on your pan, and you can use a deep pan without having to trim the front edge of the crossmember. I'd recommend removing the bolts that attach the crossmember to the chassis. Then install your transmission, and attach the transmission to the crossmember with the two mounting bolts. Make sure the crossmember is sitting perpendicular to and centered on the chassis. You can then mark the new chassis hole locations and drill away. This is way easier if your cab is off. If it's not, it'll be a challenge to drill the upper holes.



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