04-21-2017, 11:42 AM | #1 |
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LS to TH350
Ready to drop a gen3 vortec in 85 c10. Turbo 350 is already in the truck. I know I'll need the spacer plate and the longer bolts but can anyone who has done this before tell me if I'll need a new flexplate and starter as well? I'll be reusing the stock converter and the stock starter that came with the engine for now.
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04-21-2017, 01:18 PM | #2 |
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Re: LS to TH350
I've never done an automatic LS, but with the manuals you face the dilemma where the flywheel face depth is 0.400 more shallow than the classic block, so I got a specialized flywheel that was that much thicker.
Maybe the spacer plate you refer to takes up that difference? I'm in for the solution because I'm curious!
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04-21-2017, 01:45 PM | #3 |
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Re: LS to TH350
Yeah I'm definitely sure the spacer makes that up. I'm not sure if a new flexplate and starter is necessary. In all the research I've done I haven't heard a definite yes or no on those
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04-24-2017, 02:09 PM | #4 |
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Re: LS to TH350
I just installed a 2003 5.3l from a Silverado in my 79 Silverado, and the easiest way to do it is to buy the hub adapter and use the stock LS flexplate. Then you just use standard torque converter bolts. The only thing you may have to do is open the mounting holes up a little on the flexplate. I didn't have to on mine because it'd already been mated to a TH400 when I bought it. You may also have to trim outer ear on the th350 depending on which exhaust manifolds / headers you use. I used the cheap headers they sell on ebay for swaps and had to trim the passenger side slightly.
https://www.amazon.com/Torque-Conver...4P4QWQ6WEVZZN6
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04-24-2017, 02:11 PM | #5 |
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Re: LS to TH350
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04-26-2017, 10:45 AM | #6 |
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Re: LS to TH350
I'll check that out. Thanks!
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04-26-2017, 02:18 PM | #7 |
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Re: LS to TH350
I have a th400 but the process should be the same. I used a spacer and stock ls flexplate. I had to open up the holes a little bit to get the 3 bolt torque converter on, but other than that, it bolted right up. I reused the factory starter. 2 of the holes on the engine/ transmission don't line up, so don't be concerned about that when you begin to fasten the two together
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04-26-2017, 10:39 PM | #8 |
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Re: LS to TH350
Working on swapping a LQ4 6.0 into my 72 K10. Stock LS starter is fine. My flex plate was the flat version and all I had to do was enlarge the bolt holes...4L80E has 6 bolts and the TH350 has 3. My tranny is in stock position and it is a tight fit to firewall, but so was the HEI distributor. I did not want the hassle of adjusting the drive shafts as mine is a 4x4, so I went with stock position. Fired mine up last weekend just to see if it would run and it ran great.
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04-27-2017, 10:52 AM | #9 | |
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Re: LS to TH350
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04-27-2017, 11:49 AM | #10 |
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Re: LS to TH350
bellhousing to engine dowel and bolt pattern is the same..except for one bolt..its a non issue..be sure to use 2 dowels..
I think he's referring to the number of torque convertor bolts..6 instead of 3 |
04-28-2017, 10:22 AM | #11 |
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Re: LS to TH350
Yes the torque convertor bolts are what I am referring to.
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05-01-2017, 12:51 PM | #12 |
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Re: LS to TH350
I have one last question. Do any of you guys know what years of flex plates are interchangeable? For example, I went to a couple local junk yards this weekend and saw a lot of vehicles with the flex plate still in. The motor had been pulled or the trans pulled. I can't imaging GM making several different flex plates. My engine came off a 2000 silverado 1500. Anyone know what years I can pull from and still get what i need?
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05-01-2017, 12:54 PM | #13 |
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Re: LS to TH350
I can't say for sure, but I believe the flexplate from any 4l60e engine should work with the sleeve to mate to the th350. I've never read about any differences from year to year on the flexplate, though admittedly I've never had a reason to research that specifically.
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09-21-2020, 01:21 AM | #14 | |
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Re: LS to TH350
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12-16-2021, 11:11 AM | #15 | |
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Re: LS to TH350
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12-16-2021, 12:54 PM | #16 |
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Re: LS to TH350
I'll throw this in, on mine I used the ol Ebay adapter plates, the ones that locate the rear of the LS engine in the same location as the ol sbc...the clam shells bolt to them, and it sits right in there.
Then your trans and driveshaft stay in their original location
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12-16-2021, 12:59 PM | #17 | |
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Re: LS to TH350
Quote:
There's so many options, it's hard to tell which ones are going to put the rear of the engine in the stock location. What you describe sounds like it should work for me though. |
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12-16-2021, 06:20 PM | #18 |
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Re: LS to TH350
Yeah, mine have just one set of holes..
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Mongo...aka Greg RIP Dad RIP Jesse 1981 C30 LQ9 NV4500..http://67-72chevytrucks.com/vboard/s...d.php?t=753598 Mongos AD- LS3 TR6060...http://67-72chevytrucks.com/vboard/s...34#post8522334 Columbus..the 1957 IH 4x4...http://67-72chevytrucks.com/vboard/s...63#post8082563 2023 Chevy Z71..daily driver |
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