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LTX and LSXPutting LT1s, LS1s, and their variants into Third Gens is becoming more popular. This board is for those who are doing and have done the swaps so they can discuss all of their technical aspects including repairs, swap info, and performance upgrades.
I need a little advice and have had a hard time finding the info.
I am going to be doing my LS swap the end of this year. I have swapped out most of my suspension components already, with the exception of the torque arm. I was looking at the UMI torque arm and crossmember but that wont work with the 4l60e I plan to put it from what I have gathered.
I am looking for a torque arm that I can install now but still use after the swap and the correct crossmember to use during the swap, or if there is one that will work on the 700r4 and 4l60e. I dont want to spend money on a crossmember now and then have to buy another this winter. I will be using the LSX K member from UMI as well.
I don't know offhand of any transmission crossmember that will work with both TH700 and LS-style 4L60E.
One option is a BMR Trak Pak, which uses its own crossmember for the torque arm mount. Doesn't matter which transmission you're using to use it. You do need subframe connectors to mount the crossmember to, though.
Use the Holley / Hooker crossmember which accepts a full length factory torque arm on the crossmember and can handle just about any transmission you want to put in the car before and after the LS swap. Worst case you might have to buy a mounting tab for the crossmember during the swap but the main crossmember will work with both systems.
Use the Holley / Hooker crossmember which accepts a full length factory torque arm on the crossmember and can handle just about any transmission you want to put in the car before and after the LS swap. Worst case you might have to buy a mounting tab for the crossmember during the swap but the main crossmember will work with both systems.
I just started looking into this mount this weekend and was thinking the same thing. It looks like I would have to fab up a bracket for my 700r4 similar to the one purchased from Holley for the 4l60, but the ability to bolt it on and switch out when necessary is a nice option. Might need to order this up
I looked up the Hooker Blackheart info in anticipation of suggesting it, but then I figured the high price and no TH700 support would be deal killers for you. I eventually plan on going to it if/when I up my power sometime in the future - I assume my 4L60E limits will be stretched then, so I'll have to do something else. I would do the whole Blackheart exhaust at the same time.
But, having said all that, the Trak Pak really is a sweet setup. It don't care what transmission you have. And it hooked great in my LS1/T56 car.
I have no experience with a welder so I kind of like the bolt on solutions but I will check out the Trak Pak. Is there any issue or advantage with having a shorter torque arm?
A shorter torque arm lifts the rear more at launch, which tends to plant the tires harder.
The Trak Pak isn't what I would call a "short" TA. It is slightly shorter than stock /transmission mount, but not as short as a Jester tunnel saddle mount, for instance.
I will definitely look into this. My concern with the Hooker system is some people seem to have issues if not using ALL the Hooker components, while others have no issue. It is hard to justify $300 plus the 4l60e bracket if I have to get a grinder out.
Any real difference between the BMR and UMI models? Having only UMI components right now I am kind of partial to them.
I looked up the Hooker Blackheart info in anticipation of suggesting it, but then I figured the high price and no TH700 support would be deal killers for you. I eventually plan on going to it if/when I up my power sometime in the future - I assume my 4L60E limits will be stretched then, so I'll have to do something else. I would do the whole Blackheart exhaust at the same time.
But, having said all that, the Trak Pak really is a sweet setup. It don't care what transmission you have. And it hooked great in my LS1/T56 car.
I contacted holly regarding this set up and informed them that I have the older 93-97 style 4L60e (same mounts as 700R4) and not the 98+ 4l60E. They told me that their adapter plate 71223003 should work for the older style 4L60E as well. This is per "Woody Warren" from Holly who replied to my email.
I contacted holly regarding this set up and informed them that I have the older 93-97 style 4L60e (same mounts as 700R4) and not the 98+ 4l60E. They told me that their adapter plate 71223003 should work for the older style 4L60E as well. This is per "Woody Warren" from Holly who replied to my email.
I have picked this up. I may try and see how my trans mounts up with it to see if it's even feasable. My LS is still months from being ready to install in the car but I could possibly throw it in just to mock it up and see...
I contacted holly regarding this set up and informed them that I have the older 93-97 style 4L60e (same mounts as 700R4) and not the 98+ 4l60E. They told me that their adapter plate 71223003 should work for the older style 4L60E as well. This is per "Woody Warren" from Holly who replied to my email.
I caught your post here and thought I'd pass some more detailed info to you...if your transmission is a first-design, one-piece case version of the 4L60E, then the Hooker adapter bracket for the 4L60-4L70 transmission is not going to directly pick-up the mount of your transmission; Woody's information was incorrect in this instance.
The distance from the bellhousing face to the mount on your transmission is about 22-3/8" and the same measurement on a later multi-piece case 4L60-4L70 is 2" further back and located in the extension housing.
The mount location on the 700R4/1st-design 4L60 was too far forward to accomodate them during the development of the Hooker crossmember without requiring an unacceptable amount of cantilever to be put into an specific adapter bracket for those transmissions. That is the sole reason those transmissions were not covered in the application.
Thanks for the update, Todd. I had it in my head your crossmember wouldn't work with the earlier forward-mount location of the TH700/4L60.
It sure looks like a nice piece for the later transmissions, though. I especially like the extra mount bolts you added on the back side. Should improve the support by eliminating the cantilever nature of using only the factory mount bolts.
I caught your post here and thought I'd pass some more detailed info to you...if your transmission is a first-design, one-piece case version of the 4L60E, then the Hooker adapter bracket for the 4L60-4L70 transmission is not going to directly pick-up the mount of your transmission; Woody's information was incorrect in this instance.
The distance from the bellhousing face to the mount on your transmission is about 22-3/8" and the same measurement on a later multi-piece case 4L60-4L70 is 2" further back and located in the extension housing.
The mount location on the 700R4/1st-design 4L60 was too far forward to accomodate them during the development of the Hooker crossmember without requiring an unacceptable amount of cantilever to be put into an specific adapter bracket for those transmissions. That is the sole reason those transmissions were not covered in the application.
Thank you for the info toddoky! I thought about ordering the crossmember and the 4l60 bracket to get some base parameters to design up a bracket to use with my 700r4 thinking maybe I could add some gussets or maybe increase the stock size, but I just assume wait until my swap. I will look further into the trak pak or just suck it up and keep my stock torque arm for the time being.
I caught your post here and thought I'd pass some more detailed info to you...if your transmission is a first-design, one-piece case version of the 4L60E, then the Hooker adapter bracket for the 4L60-4L70 transmission is not going to directly pick-up the mount of your transmission; Woody's information was incorrect in this instance.
The distance from the bellhousing face to the mount on your transmission is about 22-3/8" and the same measurement on a later multi-piece case 4L60-4L70 is 2" further back and located in the extension housing.
The mount location on the 700R4/1st-design 4L60 was too far forward to accomodate them during the development of the Hooker crossmember without requiring an unacceptable amount of cantilever to be put into an specific adapter bracket for those transmissions. That is the sole reason those transmissions were not covered in the application.
Toddoky,
That's super depressing to hear. The whole reason i was going to use the first gen 4L60E was so I could use a 93 model year and keep my mechanical speedo working without going to some aftermarket hack-box that won't work well or will fail after a year or so.
So doing some more research, I found this article that shows a part number of a tailshaft housing extension that, when swapped in place of the factory tailshaft housing, puts the trans mount point in the TH400 location. On the surface, this seems as if it would work by using your TH400 adapter with your cross member.
In the chart above, I have included the measurements for the TH700R4/4L60 transmission with the "24214689" extension housing. This is the easiest solution I have found when you are replacing a TH400 with a TH700R4/4L60 because it adds a second mounting pad on the extension housing that you can use, and that new mounting pad is much close to the original TH400 mounting positions. Depending on the specific TH400 extension housing your vehicle came with originally, this extension housing places the trans mount anywhere from 1 1/16" (short extension housing), to 11/32" (long extension housing), to just 1/16" (medium extension housing) further rearward. I have the worst case scenario in my application, using the short extension housing, so have to deal with the mount being 1 1/16" further rearward that the original TH400 mount. Those of you with the medium extension housing only need to elongate the existing holes by 1/16" with the proper size drill bit, those of you with the long extension housing need to go a bit more at 11/32" - just a little bit more than 1/4".
Thanks for the update, Todd. I had it in my head your crossmember wouldn't work with the earlier forward-mount location of the TH700/4L60.
It sure looks like a nice piece for the later transmissions, though. I especially like the extra mount bolts you added on the back side. Should improve the support by eliminating the cantilever nature of using only the factory mount bolts.
I wish something could have been worked out for the Powerglide TH350 and 700R4/early 4L60, but it would have required a completely different crossmember as there's a 10" span disparity between the shortest (Powerglide/TH350) and longest (4L80/4L85) transmission mount locations on all the GM automatics, so you can't can't cover them all unless the vehicle frame permits moving the crossmember assembly forward. Because of the nature of the design of the floor rails under the 3rd-gens, that isn't possible.
Maybe the design of another crossmember can be revisited in the future, but it won't happen on this year's development schedule.
That's super depressing to hear. The whole reason i was going to use the first gen 4L60E was so I could use a 93 model year and keep my mechanical speedo working without going to some aftermarket hack-box that won't work well or will fail after a year or so.
So doing some more research, I found this article that shows a part number of a tailshaft housing extension that, when swapped in place of the factory tailshaft housing, puts the trans mount point in the TH400 location. On the surface, this seems as if it would work by using your TH400 adapter with your cross member.
In the chart above, I have included the measurements for the TH700R4/4L60 transmission with the "24214689" extension housing. This is the easiest solution I have found when you are replacing a TH400 with a TH700R4/4L60 because it adds a second mounting pad on the extension housing that you can use, and that new mounting pad is much close to the original TH400 mounting positions. Depending on the specific TH400 extension housing your vehicle came with originally, this extension housing places the trans mount anywhere from 1 1/16" (short extension housing), to 11/32" (long extension housing), to just 1/16" (medium extension housing) further rearward. I have the worst case scenario in my application, using the short extension housing, so have to deal with the mount being 1 1/16" further rearward that the original TH400 mount. Those of you with the medium extension housing only need to elongate the existing holes by 1/16" with the proper size drill bit, those of you with the long extension housing need to go a bit more at 11/32" - just a little bit more than 1/4".
Thoughts?
Theoretically that should indeed work, but I can't say it absolutely will as I've never personally confirmed the geometry is as stated.
Theoretically that should indeed work, but I can't say it absolutely will as I've never personally confirmed the geometry is as stated.
Well, I suppose I can call myself the Guinea pig then for this one. I have both a 700R and that 93 4L60 in my garage. When my cross member and motor mounts arrive I'll look at bolting the trans to the motor and will mock it up and see what shakes out.
There's some excellent information supplied by toddoky starting at the top of page 12.
I have the Hooker crossmember on order and will be using it with an early style 4L60 case and a Caprice extension housing with the integral rear trans mount. This just about replicates the dimensions of a TH400.
I doubt it will be a drop in but it'll be close.
There's some excellent information supplied by toddoky starting at the top of page 12.
I have the Hooker crossmember on order and will be using it with an early style 4L60 case and a Caprice extension housing with the integral rear trans mount. This just about replicates the dimensions of a TH400.
I doubt it will be a drop in but it'll be close.
Keep us updated. I'm gonna run a th400 and had thought about buying this crossmember. I've got a BMR kmember so I just read some people were having problems. Of course I haven't ran my exhaust yet so that helps.
My discussions with toddoky were extremely helpful and gave me some optimism with the fitment (even though I have 4L60 w/ Caprice extension housing rather than a TH400).
And using the different extension housing forces me to relocate the torque arm so this crossmember satisfies that requirement (as it would for a TH400).
The added clearance for exhaust is a plus.
As for updating, because of my new work schedule, I'm only around to work on the car one week out of the month so progress will be slow (as in nothing until the 1st week of May). That said, once the crossmember arrives, installation should be fairly rapid as I've most of the supporting parts in place and ready to go. Or, so I'm hoping.
My discussions with toddoky were extremely helpful and gave me some optimism with the fitment (even though I have 4L60 w/ Caprice extension housing rather than a TH400).
And using the different extension housing forces me to relocate the torque arm so this crossmember satisfies that requirement (as it would for a TH400).
The added clearance for exhaust is a plus.
As for updating, because of my new work schedule, I'm only around to work on the car one week out of the month so progress will be slow (as in nothing until the 1st week of May). That said, once the crossmember arrives, installation should be fairly rapid as I've most of the supporting parts in place and ready to go. Or, so I'm hoping.
We seem to have basically the same set up then. I look forward to seeing how yours fits and if there is any mods needed since we should be in the TH400 mounting location with this tailshaft housing.
03-23-2017, 09:23 PM
