Ls swap motor mount and clearance questions - Page 2 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**truckdude239** · 08-26-2013, 07:20 AM

I used d dingo mounts and still had to shorten mine but the linkage did line up
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Robznob11 · 08-26-2013, 08:08 AM

I would love to have a scale to see but im pretty sure you gain more than 40 lb change with every inch of setback. I re worked my firewall and went 2.5" back so the headders would clear the lower a arm
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WickedDirtBag · 08-30-2013, 09:42 PM

Ok guys picked up the 5.3/4l60e combo on Wednesday (woot woot). Just finished pulling the 350/th350 five minutes ago. The transmissions are the same length but here's the rub so far. The trans mount to end of tail shaft on the th350 is like 10.5" (crude measuring) on the 4l60e mount to end of tail is 7" (again crude measuring) . So I'm going to move the trans cross member back 3 to 3.5" to mate with driveshaft. So no need to change drive shaft at all. Anyone know of any issues with this? Making my own motor mount adapters so I got that covered as far as the move. Just gonna make it up as I go just so excited had to share my thoughts quick. Check ya all later.
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BR3W CITY · 08-31-2013, 12:27 AM

sliding the trans xmember forward or back a few inches is commonplace, there are too many engine/tranny combo's and pretty much all of them just need the xmember moved a bit to accomodate.

Between the trans and the engine adapters, just make sure that the combo sits with a bit of a rear tilt, "normal" is about 4* down, with the truck level.

Blackpony · 08-31-2013, 10:02 AM

Quote:

Originally Posted by WickedDirtBag

Ok guys picked up the 5.3/4l60e combo on Wednesday (woot woot). Just finished pulling the 350/th350 five minutes ago. The transmissions are the same length but here's the rub so far. The trans mount to end of tail shaft on the th350 is like 10.5" (crude measuring) on the 4l60e mount to end of tail is 7" (again crude measuring) . So I'm going to move the trans cross member back 3 to 3.5" to mate with driveshaft. So no need to change drive shaft at all. Anyone know of any issues with this? Making my own motor mount adapters so I got that covered as far as the move. Just gonna make it up as I go just so excited had to share my thoughts quick. Check ya all later.
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This is exactly what I did on my truck. I am yet to have an issue. Was able to bolt the stock linkage up also with no modifications. Good luck with it!!
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WickedDirtBag · 09-01-2013, 10:49 PM

Alright guys just slid the trans member back 3.5 inches and noticed I could see the holes on the crossmember just peeking through another set of factory holes on the frame. So I tapped it back and put the bolts through so I ended up shifting the trans member back 3.75 inches. Haven't moved trans and motor back yet but looks like it will all clear nicely. My only concern is the quarter inch difference in relation to the driveshaft. Is the driveshaft seating into trans a quarter inch further going to be an issue or am I over thinking things? I am going to be dropping the rear three inches in the future so I may have to shorten it anyway. Let me know your thoughts . Can't wait to fire her up!!!
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BR3W CITY · 09-02-2013, 12:55 AM

its not a problem so long as the shaft never binds or "Bottoms out" onto the splines. You can mess up the splines, the tailshaft seal, or even stuff like the output shaft if something really gnarly occurred.

BigRed76 · 09-08-2013, 12:04 AM

Read all of the posts but didn't see any mention of what year your truck is and longbed or shortbed, but if it's a longbed then the front driveshaft at the transmission won't move with suspension travel so you shouldn't have to worry about any binding. But if you've got a shortbed with a 1 pc. shaft then it's pretty critical for spacing on the slip yoke on the driveshaft.

WickedDirtBag · 09-08-2013, 02:21 PM

It's a 69 long bed and once I got into the carrier bearing issue I realized binding wouldn't be an issue. Got the motor bolted in bunch of trial and error but its in. Rainin out today so the harness is getting gone thru to make it standalone. Soo many wires!!! Exercise in patience today.
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BigRed76 · 09-08-2013, 05:48 PM

Quote:

Originally Posted by WickedDirtBag

It's a 69 long bed and once I got into the carrier bearing issue I realized binding wouldn't be an issue. Got the motor bolted in bunch of trial and error but its in. Rainin out today so the harness is getting gone thru to make it standalone. Soo many wires!!! Exercise in patience today.
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Good deal. There are lots of wires to remove, but it's possible with patience. And saves you quite a bit of money too.

08-26-2013, 07:20 AM	#26
truckdude239 Senior Member Join Date: Sep 2005 Location: Lewisville, Nc Posts: 10,237	Re: Ls swap motor mount and clearance questions I used d dingo mounts and still had to shorten mine but the linkage did line up Posted via Mobile Device __________________ David fuller Ase Certified Mechanic Click here to help support our board!! 1971 Chevy c-10 under going a 4.8l LSx swap Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305 2007 Honda Accord my daily 145kmiles 2002 Honda Accord 4 door With 330k(sisters car) 2005 toyota Avalon 228k( brothers car) 2002 Sububran 5.3 245k 2000 Tahoe 5.3l 378 General manager for Marco's Carwash & lube

08-26-2013, 08:08 AM	#27
Robznob11 Registered User Join Date: Feb 2004 Location: brownfield texas (west texas) Posts: 1,936	Re: Ls swap motor mount and clearance questions I would love to have a scale to see but im pretty sure you gain more than 40 lb change with every inch of setback. I re worked my firewall and went 2.5" back so the headders would clear the lower a arm Posted via Mobile Device __________________ The Ghost 67 short wide full custom. 550 hp LSX, 4l80E, narrowed 9". Body dropped w/air ride! ........................ ___ .........________//__{\_____ ,,,,,,,/__(⊙)___//___/__(O)_/ @disciple2.rc 💪instagram💪 LED TAILS

08-30-2013, 09:42 PM	#28
WickedDirtBag Registered User Join Date: May 2013 Location: Clear Lake , WI Posts: 17	Re: Ls swap motor mount and clearance questions Ok guys picked up the 5.3/4l60e combo on Wednesday (woot woot). Just finished pulling the 350/th350 five minutes ago. The transmissions are the same length but here's the rub so far. The trans mount to end of tail shaft on the th350 is like 10.5" (crude measuring) on the 4l60e mount to end of tail is 7" (again crude measuring) . So I'm going to move the trans cross member back 3 to 3.5" to mate with driveshaft. So no need to change drive shaft at all. Anyone know of any issues with this? Making my own motor mount adapters so I got that covered as far as the move. Just gonna make it up as I go just so excited had to share my thoughts quick. Check ya all later. Posted via Mobile Device

08-31-2013, 12:27 AM	#29
BR3W CITY meowMEOWmeowMEOW Join Date: Sep 2009 Location: MKE WI Posts: 7,128	Re: Ls swap motor mount and clearance questions sliding the trans xmember forward or back a few inches is commonplace, there are too many engine/tranny combo's and pretty much all of them just need the xmember moved a bit to accomodate. Between the trans and the engine adapters, just make sure that the combo sits with a bit of a rear tilt, "normal" is about 4* down, with the truck level. __________________ *'66 Short Step / SD Tuned / Big Cam LQ4 / Backhalfed /Built 4l80e / #REBUILDEVERYTHING* MY BUILD THE H8RDCPTR //\\ MY YOUTUBE CHANNEL REV J HD

09-01-2013, 10:49 PM	#31
WickedDirtBag Registered User Join Date: May 2013 Location: Clear Lake , WI Posts: 17	Re: Ls swap motor mount and clearance questions Alright guys just slid the trans member back 3.5 inches and noticed I could see the holes on the crossmember just peeking through another set of factory holes on the frame. So I tapped it back and put the bolts through so I ended up shifting the trans member back 3.75 inches. Haven't moved trans and motor back yet but looks like it will all clear nicely. My only concern is the quarter inch difference in relation to the driveshaft. Is the driveshaft seating into trans a quarter inch further going to be an issue or am I over thinking things? I am going to be dropping the rear three inches in the future so I may have to shorten it anyway. Let me know your thoughts . Can't wait to fire her up!!! Posted via Mobile Device

09-02-2013, 12:55 AM	#32
BR3W CITY meowMEOWmeowMEOW Join Date: Sep 2009 Location: MKE WI Posts: 7,128	Re: Ls swap motor mount and clearance questions its not a problem so long as the shaft never binds or "Bottoms out" onto the splines. You can mess up the splines, the tailshaft seal, or even stuff like the output shaft if something really gnarly occurred. __________________ *'66 Short Step / SD Tuned / Big Cam LQ4 / Backhalfed /Built 4l80e / #REBUILDEVERYTHING* MY BUILD THE H8RDCPTR //\\ MY YOUTUBE CHANNEL REV J HD

09-08-2013, 12:04 AM	#33
BigRed76 Registered User Join Date: Jan 2010 Location: Loveland, CO Posts: 1,921	Re: Ls swap motor mount and clearance questions Read all of the posts but didn't see any mention of what year your truck is and longbed or shortbed, but if it's a longbed then the front driveshaft at the transmission won't move with suspension travel so you shouldn't have to worry about any binding. But if you've got a shortbed with a 1 pc. shaft then it's pretty critical for spacing on the slip yoke on the driveshaft. __________________ Zach 1970 Chevrolet Custom Camper K20 1971 GMC Super K2500, 12V/NV4500 swap in progress 1971 Chevrolet Custom C10 1972 Chevrolet Custom Deluxe C20, 5.3/4L60E 1972 Oldsmobile Cutlass Supreme, 455/TH400, 3.73 posi 2004 GMC Sierra 2500HD, LB7/Allison, CCSB 2005 GMC Sierra 1500, 5.3/4L60E, CCSB

09-08-2013, 02:21 PM	#34
WickedDirtBag Registered User Join Date: May 2013 Location: Clear Lake , WI Posts: 17	Re: Ls swap motor mount and clearance questions It's a 69 long bed and once I got into the carrier bearing issue I realized binding wouldn't be an issue. Got the motor bolted in bunch of trial and error but its in. Rainin out today so the harness is getting gone thru to make it standalone. Soo many wires!!! Exercise in patience today. Posted via Mobile Device



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