th350-700r4 mounting - The 1947 - Present Chevrolet & GMC Truck Message Board Network

rodstored-72 · 08-28-2005, 12:10 AM

all,
i am in the process of installing a new 700r4 trans from a th350 short tail. i don't have the new trans yet, but i am wanting to move the x-member to the correct location. i have paperwork stating that the difference in the mounting points of the two trannys. th350 is 20-3/8" from bell face to mount holes & for the 700r4 it is 22-1/2" from same point of reference. my questions are:

1) would it be safe to move & mount the x-member using the difference in measurements??? & has anyone done it like this before???

2) the trans place said that they would (could) do it, but i have the truck cab off & the engine is just installed. with just the suspension together.

i would like to put the member in the correct location myself, but i would need a mock up trans. to be sure it was right. i am not sure how to handle this siuation. i would like any input from you guys & gals. it would be great if someone who has rebuilt their truck could give me some suggs. or ideas or little "secrets" that they learned. the truck is all apart right now. i want the shop to actually mount the trans. & hook everything together. but i would like to have the x-member mounted before they install the tranny.

thanks for all of the input from everone in advance!!!

i am going to try to post some pics of the rebuild so far, if i can fiure out how to!!

thanks all!!!

rodstored-72

69 longhorn · 08-28-2005, 12:32 AM

Bolt the R4 up , & slide the crossmember where it needs to be......maybe not a lot of help, but when you are "modin", you are fitting pcs. best of luck,crazyL

**VetteVet** · 08-28-2005, 12:40 AM

Here is a good thread to help you.

http://67-72chevytrucks.com/vboard/s...d.php3?t=33266

**pjmoreland** · 08-29-2005, 03:44 AM

From what I've heard, there are two styles of 700R4 tail housings. Some of the earlier housings have an extra crossmember mounting location that is farther back on the housing. The nice thing about the mounting location that is farther back is that it gets the crossmember out of the way of the pan on the bottom of the transmission. I used the newer style of housing that put my crossmember right up close to the pan. I had to trim about 1/2" off the front edge of the crossmember when I installed a high-capacity pan.

I would be a little nervous about trying to drill the holes ahead of time. If they end up being wrong, you will have to slot the holes. There is a small amount of adjustment on the motor mount towers that could help compensate.

Jakes-66-K10 · 08-29-2005, 09:48 AM

I agree with pmjoreland, even though you could go with printed dimensions - I'd have a little patience. Wait for the 700r4 tranny you'll use to mark where the crossmember needs to be.

Just some additional feedback, I used the original 350 crossmember but did not use the center holes into the transmission mount. I drilled two new holes in the center, an inch and a half back, so that the lip of the crossmember does not interfere with removing pan bolts. So where my crossmember sits, I have a straight shot to all bolts. If I used the original mount hole locations to the tranny mount, it'd be a pain to remove the pan.

67ChevyRedneck · 08-29-2005, 10:11 AM

Since it's already stripped to the frame your truck isn't going anywhere soon. Be patient and wait for your tranny. When I did mine I used what would have been the back 2 bolt holes for the th-350 mount as the front two holes for where my 700R4 went, and drilled two new back holes for it. It's a pain to drill holes, these frames are thick!

rodstored-72 · 08-29-2005, 10:29 AM

thanks for all the feedback, i was thinking along the same lines, but how do i get ahold of the trans to mock up the mounting.... would the trans shop let me "borrow" a trans to use for mock up if i tell them that i will still let them do the install ???

Jakes-66-K10 · 08-29-2005, 01:51 PM

Why not just wait and use the tranny you plan on driving with? If the tranny shop is doing the install, as long as you HAVE a crossmember they probably won't think twice about bolting it in where it needs to go. I guess I don't see why you think you need to have this done, if they are doing the install anyway?

rodstored-72 · 08-29-2005, 03:35 PM

the reason that i want to mount the member first is that i have the cab off & just finished painting the frame. i would like to mount the member in the correct position, then paint the area over, then mount the cab & then have the shop mount the trans. for me to get all the cable linkage and everything else hooked up correctly. sorry if i am not making sense, i am new at this & this is what i thought would be the best..
thanks again for all the input, to me this is what it is all about!!!

thanks!!

rodstored-72

**pjmoreland** · 08-29-2005, 05:23 PM

It will be way easier to drill the top holes for the crossmember without the cab in place.

rodstored-72 · 08-29-2005, 06:57 PM

pjmoreland, yea agree that is why i am trying to get some more info. i just dont know how to get ("borrow") a trans. case to bolt up to the motor to use as mock up. i thought that i might be able to "borrow" one from the trans place, do the member location & then give it back to the shop w/o damage or anything. it should only take about a day to bolt it on & do the mock up.

any suggestions would still be greatly appreciated.

thanks again everyone...

rodstored-72

acloco · 08-29-2005, 07:48 PM

The trans shop will have a junk R4 trans case laying around....guaranteed.

Jakes-66-K10 · 08-30-2005, 07:17 PM

rodstored, I just noticed your in Arizona - so this may be an option for you since you aren't too far away. I have a 700r4 that shifts and everything you could use to put your crossmember in place. I'd sell it to you at the cost of what transmission shops charge if you don't have a core to rebuild. Perhaps that will help, you can leave this tranny in and build around it. When your truck is done you can use this until you get a new one, so you don't have to pay a core charge. PM if you're interested.

**Downtown** · 08-30-2005, 11:36 PM

pjmoreland is right. There are two different tailshaft housings for the 700R4. The one with the mounting farther back is from around 82-83 caprices. Those mount really nice and make the swap alot easier.

rodstored-72 · 08-31-2005, 10:20 AM

vortexofpain,
thanks for the offer. i think that i am going to go buy the shop that i am having the work done & see if they will let me barrow a casing for a day or two. if they dont then i will pm you to see about your trans. i am kinda hesitant though because i already have my old th350 laying in the side of the yard & i can't seem to get rid of it.

thanks for all the input though everyone....

rodstored-72

08-28-2005, 12:10 AM	#1
rodstored-72 chevy truck fan Join Date: Mar 2005 Location: Gilbert, arizona 85298 Posts: 1,996	th350-700r4 mounting all, i am in the process of installing a new 700r4 trans from a th350 short tail. i don't have the new trans yet, but i am wanting to move the x-member to the correct location. i have paperwork stating that the difference in the mounting points of the two trannys. th350 is 20-3/8" from bell face to mount holes & for the 700r4 it is 22-1/2" from same point of reference. my questions are: 1) would it be safe to move & mount the x-member using the difference in measurements??? & has anyone done it like this before??? 2) the trans place said that they would (could) do it, but i have the truck cab off & the engine is just installed. with just the suspension together. i would like to put the member in the correct location myself, but i would need a mock up trans. to be sure it was right. i am not sure how to handle this siuation. i would like any input from you guys & gals. it would be great if someone who has rebuilt their truck could give me some suggs. or ideas or little "secrets" that they learned. the truck is all apart right now. i want the shop to actually mount the trans. & hook everything together. but i would like to have the x-member mounted before they install the tranny. thanks for all of the input from everone in advance!!! i am going to try to post some pics of the rebuild so far, if i can fiure out how to!! thanks all!!! rodstored-72

08-28-2005, 12:32 AM	#2
69 longhorn Registered User Join Date: Aug 2001 Location: rock island,il,usa Posts: 5,382	Bolt the R4 up , & slide the crossmember where it needs to be......maybe not a lot of help, but when you are "modin", you are fitting pcs. best of luck,crazyL __________________ http://community.webshots.com/user/hotrodhorn

08-28-2005, 12:40 AM	#3
VetteVet Msgt USAF Ret Join Date: Jan 2005 Location: Kalamazoo, Michigan Posts: 8,715	700 r4 FAQ Here is a good thread to help you. http://67-72chevytrucks.com/vboard/s...d.php3?t=33266 __________________ VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative.

08-29-2005, 10:11 AM	#6
67ChevyRedneck Hittin E-Z Street on Mud Tires Join Date: Nov 2004 Location: Greenville, SC Posts: 23,090	Since it's already stripped to the frame your truck isn't going anywhere soon. Be patient and wait for your tranny. When I did mine I used what would have been the back 2 bolt holes for the th-350 mount as the front two holes for where my 700R4 went, and drilled two new back holes for it. It's a pain to drill holes, these frames are thick! __________________ Jesse James 1967 C10 SWB Stepside: 350/700R4/3.73 1965 Ford Mustang: 289/T5-5spd/3.25 Trac-Loc 1968 Pontiac Firebird: Project Fire Chicken! 2015 Silverado Double Cab 5.3L Z71 2001 Jeep Wrangler Sport 4.0L 5spd 2020 Chevrolet Equinox Premium 2.0L Turbo 2011 Mustang V6 ~ Wife's ride American Born, Country by the Grace of God 1967 CST Shop Truck Rebuild! My 1967 C-10 Build Thread My Vintage Air A/C Install Project "On a Dime" Trying my hand at Home Renovation! 1965 Mustang Modifications!

08-29-2005, 10:29 AM	#7
rodstored-72 chevy truck fan Join Date: Mar 2005 Location: Gilbert, arizona 85298 Posts: 1,996	thanks for all the feedback, i was thinking along the same lines, but how do i get ahold of the trans to mock up the mounting.... would the trans shop let me "borrow" a trans to use for mock up if i tell them that i will still let them do the install ??? Last edited by rodstored-72; 08-29-2005 at 10:36 AM.

08-29-2005, 03:44 AM	#4
pjmoreland Senior Member Join Date: Jan 2005 Location: CA Posts: 5,649	From what I've heard, there are two styles of 700R4 tail housings. Some of the earlier housings have an extra crossmember mounting location that is farther back on the housing. The nice thing about the mounting location that is farther back is that it gets the crossmember out of the way of the pan on the bottom of the transmission. I used the newer style of housing that put my crossmember right up close to the pan. I had to trim about 1/2" off the front edge of the crossmember when I installed a high-capacity pan. I would be a little nervous about trying to drill the holes ahead of time. If they end up being wrong, you will have to slot the holes. There is a small amount of adjustment on the motor mount towers that could help compensate.

08-29-2005, 09:48 AM	#5
Jakes-66-K10 Registered User Join Date: Aug 2004 Location: Idaho Posts: 640	I agree with pmjoreland, even though you could go with printed dimensions - I'd have a little patience. Wait for the 700r4 tranny you'll use to mark where the crossmember needs to be. Just some additional feedback, I used the original 350 crossmember but did not use the center holes into the transmission mount. I drilled two new holes in the center, an inch and a half back, so that the lip of the crossmember does not interfere with removing pan bolts. So where my crossmember sits, I have a straight shot to all bolts. If I used the original mount hole locations to the tranny mount, it'd be a pain to remove the pan.

08-29-2005, 01:51 PM	#8
Jakes-66-K10 Registered User Join Date: Aug 2004 Location: Idaho Posts: 640	Why not just wait and use the tranny you plan on driving with? If the tranny shop is doing the install, as long as you HAVE a crossmember they probably won't think twice about bolting it in where it needs to go. I guess I don't see why you think you need to have this done, if they are doing the install anyway?

08-29-2005, 03:35 PM	#9
rodstored-72 chevy truck fan Join Date: Mar 2005 Location: Gilbert, arizona 85298 Posts: 1,996	the reason that i want to mount the member first is that i have the cab off & just finished painting the frame. i would like to mount the member in the correct position, then paint the area over, then mount the cab & then have the shop mount the trans. for me to get all the cable linkage and everything else hooked up correctly. sorry if i am not making sense, i am new at this & this is what i thought would be the best.. thanks again for all the input, to me this is what it is all about!!! thanks!! rodstored-72

08-29-2005, 05:23 PM	#10
pjmoreland Senior Member Join Date: Jan 2005 Location: CA Posts: 5,649	It will be way easier to drill the top holes for the crossmember without the cab in place.

08-29-2005, 06:57 PM	#11
rodstored-72 chevy truck fan Join Date: Mar 2005 Location: Gilbert, arizona 85298 Posts: 1,996	pjmoreland, yea agree that is why i am trying to get some more info. i just dont know how to get ("borrow") a trans. case to bolt up to the motor to use as mock up. i thought that i might be able to "borrow" one from the trans place, do the member location & then give it back to the shop w/o damage or anything. it should only take about a day to bolt it on & do the mock up. any suggestions would still be greatly appreciated. thanks again everyone... rodstored-72

08-29-2005, 07:48 PM	#12
acloco Registered User Join Date: Apr 2004 Location: Nebraska Posts: 335	The trans shop will have a junk R4 trans case laying around....guaranteed.

08-30-2005, 07:17 PM	#13
Jakes-66-K10 Registered User Join Date: Aug 2004 Location: Idaho Posts: 640	rodstored, I just noticed your in Arizona - so this may be an option for you since you aren't too far away. I have a 700r4 that shifts and everything you could use to put your crossmember in place. I'd sell it to you at the cost of what transmission shops charge if you don't have a core to rebuild. Perhaps that will help, you can leave this tranny in and build around it. When your truck is done you can use this until you get a new one, so you don't have to pay a core charge. PM if you're interested.

08-30-2005, 11:36 PM	#14
Downtown Senior Member Join Date: Dec 1999 Location: New Palestine, IN Posts: 470	pjmoreland is right. There are two different tailshaft housings for the 700R4. The one with the mounting farther back is from around 82-83 caprices. Those mount really nice and make the swap alot easier. __________________ 72 Super Cheyenne Longbed 350 49,000 original miles and My dad ordered it new 66 Chevy Caprice 2 dr 77 Caprice Estate Wagon New Palestine, IN

08-31-2005, 10:20 AM	#15
rodstored-72 chevy truck fan Join Date: Mar 2005 Location: Gilbert, arizona 85298 Posts: 1,996	vortexofpain, thanks for the offer. i think that i am going to go buy the shop that i am having the work done & see if they will let me barrow a casing for a day or two. if they dont then i will pm you to see about your trans. i am kinda hesitant though because i already have my old th350 laying in the side of the yard & i can't seem to get rid of it. thanks for all the input though everyone.... rodstored-72



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