Team,
Earlier this year I had everything out of my car. The SBC350 the TH350 and the 10 bolt. Well last week I got a new 12 bolt under the car. Yesterday I decided it was time to put in the freshened up 350 and a new 700R4. The 700R4 is out of a 91 truck. I noticed the trans mount that was on it had a stud and would not fit with my cross member. So I removed the one off my TH350 and bolted it on. As we lowered the engine/trans combo in things started to get tight. I had to remove the TCI lockup wiring because it was in the way of the tunnel. I then had to remove the sheetmetal shift bracket on the 700R4 because it was hitting the tunnel. I figured once I got the engine and trans bolted in there would be enough room to reinstall these items. I then realized things were getting tighter than I thought they should. The trans cross member was clearly in the way (it had already been moved 3 inchs back for the 700R4). So I unbolted it and slid it all the way back and out of the way. Eventally we got the motor mounts bolted up. We then went under the car to attempt to slide the cross member under the trans and bolt it in. Well we then realized we had a large problem. We could no longer lift the trans any higher because it was hitting the tunnel/floor of the car. You could hear it smashing sheetmetal as you attempted to raise it any higher and we were nowhere close to being able to slide the cross member under. See picture (this is with trans hitting the floor).
http://s200.photobucket.com/albums/aa265/dauber65/engine_trans_install/?action=view&current=100_1057.jpg
I'm not sure what is going on here. Possibly the wrong trans mount (even though this one is off the existing TH350). Maybe I installed the cross member upside down/backwards (I doubt, but I did take it out for paint). Maybe there is something wrong with my cross member all together. I thought this was a simple plug and play, but something bad is going on. Here are some more pictures from yesterday.
http://s200.photobucket.com/albums/aa265/dauber65/engine_trans_install/

How much lower is the stock 700 tranny mount?
The tranny looks too high.

Dave

The R4 is quite a bit bigger in diameter than a T350. I had to refab the floor in my '33 when I did the swap. The R4 hit the floor bigtime right where it transitions from "bellhousing" to case.

The mount I pulled off the 700R4 (with a single stud that I could not use) was not as thick as the mount that I pulled off the TH350. Maybe I should be getting a new trans mount, but I don't know what to ask for at the parts store. Even with a touch shorter mount, I don't know if I've going to get the room I need. Especially the area for the shifter bracket on the side. I thought from others this was a simple drop in situation. I'm starting to get a little worried.

I took out a power glide and installed a 700r4 in my 69, I had no problems except for the trans. crossmember had to be shifted back about 3 inches or so.
It was a couple of years ago, but I don't remember if I had to change the mount or if I used the power glides mount, sorry.

There should be more than enough room in the tunnel for the 700 to fit.

You may have to get a different crossmember designed for the 700R4. I know in my 65 I bought a crossmember which was specific for my car and the 700r4 tranny.

- Mike

My understanding is that the crossmember just goes back 3 inchs you can buy a cross member that does this, or simply move it back 3 inchs and make new holes as I had planned.
Anyone buy a new mount when they swithed to the 700R4? I'm curious how you'd order that at a parts store....... does a 87 IROC fit or something crazy like that. Obviously a 91 pickup one will not because it has the single stud in the middle, however the one that came off of it was thinner than the one off the TH350 which makes me think thinner ones are out there with the two hole set up. Can anyone tell me their thickness of one they are running?

how are your body mounts- if they are sagging, then you lost a bit of room down there- otherwise, pull the engine/trans back out and use a hammer and make that sucker fit- you will have marks from the trans case hitting the floor to tell you where you need room. it looks like it's close- 1/4" here and 1/4" there should make the room you need.

My understanding is that the crossmember just goes back 3 inchs you can buy a cross member that does this, or simply move it back 3 inchs and make new holes as I had planned.
Anyone buy a new mount when they swithed to the 700R4? I'm curious how you'd order that at a parts store....... does a 87 IROC fit or something crazy like that. Obviously a 91 pickup one will not because it has the single stud in the middle, however the one that came off of it was thinner than the one off the TH350 which makes me think thinner ones are out there with the two hole set up. Can anyone tell me their thickness of one they are running?

I just did a 350T / 700R4 swap and bought a new transmission mount at Oreily's Auto (Anchor 2378) fit right in no problems

Did you see the underside of this car? What a mess! (When I bought this car off e-bay last year and the ad said it had all new body work and paint.........ya right. The back seat is falling through the bottom of the car). Anyways, I'll get back on subject. I doubt my body mounts are any good. I hadn't really thought about that any. So has anyone else run into this problem before in a chevelle? From all the forums I read (trust me I read alot before making the 700R4 switch) it was no big deal. Never any clearance problems. Heck if I jacked the trans up a little more, with all the rust down there it might just break through the floor and end up in the car.

One more thing. Do you guys just reuse the shift bracket off the side of the 700R4 or do you use the one off the TH350?

I did not have to change the crossmember in my 69, just slid it back. I am unable to go and look at the car at this moment so I can't tell you what my trans. mount looks like.
I used either the Power glide or the 700 mount. can't remember.
I did not have to take a hammer to the tunnel.
I almost sure the 68-72 tunnel are the same.

As far as the shifter bracket goes, I bought a new B&M rachet shifter for the floor and used all the new stuff that came with the shifter.

You need to use a THM350 mount, the 700R4 mount in later cars will not work. The factory crossmember will work. I agree, check the body bushings. It is amazing how they affect the ride, handling and even fit and finish of the car.

I had no clearance issues with mine, getting someone to cut the driveshaft correctly, well that is another story.

I found this old thread..........someone else having the same issue. I restarted it because it never had a resolution. I'm starting to wonder about my cross member. Maybe I have it in there wrong or upside down or something stupid like that. It also has alot of weld splatter on it. I'm curious if someone has welded on it before. I'd be curious if anyone else can take a measurement of their 700R4 tailshaft (not sure of the best place to measue would be) to the floorpan. Maybe the middle of the speedo mounting bracket bolt or something easy to measure off of? (Can see the bolt in my picture)
http://s200.photobucket.com/albums/aa265/dauber65/engine_trans_install/?action=view&current=100_1057.jpg
Here is the thread I restarted.
http://www.chevelles.com/forums/showthread.php?p=1958316#post1958316

Use the 700 mount and drill a hole in the center of your cross member pad (between the 2 slots for 350 mount) for the stud.

Dave

That's not a horrible idea. Anyone ever done this before? I hadn't ever entertained that thought before. That mount is in rough shape but I could always buy a new 91 pickup mount.

Randy,

I used the Bowtie Overdrive crossmember for my 65 and 700R4 conversion. Another guy on this forum had the same problem as you and he solved it with the Bowtie part.

I guess the obvious question is what is different between the stock crossmember and the bowtie crossmember? I have already drilled the new set of holes 3 inchs back so that is not a concern to me. Do their cross members come with their own mount? I'd be curious if anyone could get a picture of their 700R4 mount installed on a stock crossmember (because it has clearly been done on here) or maybe just its measured height of the mount on a stock unit.

More interesting. Does anyone know if they offered different thickness trans mounts in different thicknesses for the TH350/TH400/Powerglide (all used some mount style as far as I know).
It wouldn't suprise me if the one off my old TH350 was wrong because lots of things have been wrong off that car............ including an english and metric bolt holding it to the TH350. (another great find of mine from the previous owner)

Randy,

Call Bowtie for the answer to your question. I don't know the specifics.

I did some measurments last night. The 700R4 mount I removed with one stud (that will not fit without some mods) was 1 1/2 inchs. The one that is under my car is 2 inchs thick. I got bold last night and wanted to see how far I could jack the trans. I put a jack under the mount and pushed it up. I could see the floor start to bend up I could rear some pressure coming off the front control arms, but I could get it high enough to slide the cross member under the mount. I guess my question would be......... what damage could you cause with the trans touching the floor? I also found a p/n on the bottom of my mount. ANCHOR-KOREA 2378.
That is the same part number someone recommened earlier. So it seems I have a floorpan issue.

PS~I got ahead of myself and drilled a new set of holes exactly 3 inchs back from the orginal before I did any fit up. I can get one side of these to bolt up, but then if I put a single bolt from the trans into play....... I don't even get close to the other side. Do you guys that reused your orginal know if you moved BOTH sides back 3 inchs EXACTLY. Or was this a rough estimate? I measured both set of new holes I drilled to a common reference point on each side and they are drilled in identical locations driver to passenger.

PS~I'm not ignoring your guys recommendation to go to Bowtie. In fact I have gone to them in the past for other items and they are good to work with. It is just that their cross member is pricey compared to zero dollars because I have one that will work already if it is just moved backwards (according to Chevelle folklore).

just from the hip here - chevy has two differnt styles of motor mounts. later model small block mounts typically have a higher setting than the ones used on the early models like on my 67 chevelle has. try the short and wide version instead. usually available for about 10 bucks each at the parts store of your choice.

I did some measurments last night. The 700R4 mount I removed with one stud (that will not fit without some mods) was 1 1/2 inchs. The one that is under my car is 2 inchs thick. I got bold last night and wanted to see how far I could jack the trans. I put a jack under the mount and pushed it up. I could see the floor start to bend up I could rear some pressure coming off the front control arms, but I could get it high enough to slide the cross member under the mount. I guess my question would be......... what damage could you cause with the trans touching the floor? I also found a p/n on the bottom of my mount. ANCHOR-KOREA 2378.
That is the same part number someone recommened earlier. So it seems I have a floorpan issue.

PS~I got ahead of myself and drilled a new set of holes exactly 3 inchs back from the orginal before I did any fit up. I can get one side of these to bolt up, but then if I put a single bolt from the trans into play....... I don't even get close to the other side. Do you guys that reused your orginal know if you moved BOTH sides back 3 inchs EXACTLY. Or was this a rough estimate? I measured both set of new holes I drilled to a common reference point on each side and they are drilled in identical locations driver to passenger.

"What damage could you cause with the trans touching the floor?" - - - If nothing else, you'd probably have engine/trans vibrations transmitted through the body. I had a billet servo touching the trans tunnel, on my 70', ... cause that problem.

Dauber65, I don't know how old this thread is or if you have solved the problem or not so I going to take a chance and post a possible solution. I have found that the 700R4 transmission has several styles of tail housings for different cars. I purchased a tailhousing from these guys. www.transmissionhead.com Scroll down about two thirds of their web page or search on tailhousing and you should find a tailhousing where the mount is located behind the speedo gear. Hope this helps as opposed to pounding on the trans tunnel.

Lane

Sorry couldn't post a photo.

Dauber65, Here is a link to a photo of the tailhousing.
http://pic90.picturetrail.com/VOL2227/10776425/20616648/335876318.jpg