LS swap question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Nick_c10 · 11-13-2018, 03:53 PM

I’m about to do an LS swap. As far as mounting the motor are there any modifications I will have to do to the firewall or anything else or does it bolt right in with the new motor mounts? Thanks in advance.

**1971Stepside** · 11-13-2018, 06:46 PM

Welcome to the board. No modification to the firewall on my 71. Not sure what year or LS you are working with. One thing I can tell you is to do plenty of homework. Know your AC plan, your header plan, your engine mounting plan, etc. Each piece will impact the next one. I used POL engine stands with LSX innovation adjustable plates. Kept the engine in near the same spot as the original small block. Good luck.

**mongocanfly** · 11-13-2018, 07:05 PM

/\/\/\..what he said....what yr truck,what trans?...more info please..don't expect everything to just bolt back together...remember these engines/trans wernt designed for our old trucks..

lutronjim · 11-13-2018, 11:20 PM

I put a LC9 with a 4l65e tranny in my 1970 C10. I bought motor and transmission mounts from BRPhotrods inc. See http://www.brphotrods.com/.
This was 'bout 4 years ago - I now see they have all sorts of kits.

It bolted in with no mod to frame nor body. It also has the correct trunnion angle. A 90 chev drive shaft with an adaptive u joint fit - no vibrations.

Lots of luck with project.

Nick_c10 · 11-13-2018, 11:45 PM

I haven’t bought the LS motor yet, I have my current motor and tranny sold, just waiting to find the right one. I have a 68 shortbed stepside 2wd. I am probably going to go with a 5.3 with the 4L60e tranny just because the 6.0 with the 4L80e is a lot more expensive. Thanks for the advice guys.

**Clyde65** · 11-14-2018, 03:45 PM

Nick,

Don’t count the 4.8 out! I have one and it gives plenty of power for me.

Good luck!

Nick_c10 · 11-14-2018, 05:35 PM

I’ll keep that in mind Clyde.

tbrown5079 · 11-17-2018, 06:24 PM

I also agree with Clyde, very happy with my 4.8. All I need!

11-13-2018, 03:53 PM	#1
Nick_c10 Registered User Join Date: Jan 2015 Location: Rapid City SD Posts: 31	LS swap question I’m about to do an LS swap. As far as mounting the motor are there any modifications I will have to do to the firewall or anything else or does it bolt right in with the new motor mounts? Thanks in advance.

11-13-2018, 06:46 PM	#2
1971Stepside Almost Satisfied Join Date: Mar 2002 Location: Springfield, MO Posts: 2,932	Re: LS swap question Welcome to the board. No modification to the firewall on my 71. Not sure what year or LS you are working with. One thing I can tell you is to do plenty of homework. Know your AC plan, your header plan, your engine mounting plan, etc. Each piece will impact the next one. I used POL engine stands with LSX innovation adjustable plates. Kept the engine in near the same spot as the original small block. Good luck. __________________ 1971 C10 Stepside. LSx 6.0 with BTR Stage IV, Speed Engineering Headers, 4L80e transmission w/3200 Circle-D Stall. 3.73. Posi. Purchased this truck when I was 17. I started the rebuild (or take apart) in 1993. I have drug it around all over the country in pieces. Finally back on the road in 2021. "I can't complain, but sometimes I still do. Life's been good to me so far."

11-13-2018, 07:05 PM	#3
mongocanfly Post Whore Join Date: May 2015 Location: Alabama Posts: 14,671	Re: LS swap question /\/\/\..what he said....what yr truck,what trans?...more info please..don't expect everything to just bolt back together...remember these engines/trans wernt designed for our old trucks.. __________________ 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

11-13-2018, 11:20 PM	#4
lutronjim Registered User Join Date: Dec 2013 Location: Dunwoody,Ga Posts: 443	Re: LS swap question I put a LC9 with a 4l65e tranny in my 1970 C10. I bought motor and transmission mounts from BRPhotrods inc. See http://www.brphotrods.com/. This was 'bout 4 years ago - I now see they have all sorts of kits. It bolted in with no mod to frame nor body. It also has the correct trunnion angle. A 90 chev drive shaft with an adaptive u joint fit - no vibrations. Lots of luck with project.

11-13-2018, 11:45 PM	#5
Nick_c10 Registered User Join Date: Jan 2015 Location: Rapid City SD Posts: 31	Re: LS swap question I haven’t bought the LS motor yet, I have my current motor and tranny sold, just waiting to find the right one. I have a 68 shortbed stepside 2wd. I am probably going to go with a 5.3 with the 4L60e tranny just because the 6.0 with the 4L80e is a lot more expensive. Thanks for the advice guys.

11-14-2018, 03:45 PM	#6
Clyde65 1965 Chevy C10, 2005 4.8L/4l60 Join Date: Aug 2004 Location: DFW Texas Posts: 8,546	Re: LS swap question Nick, Don’t count the 4.8 out! I have one and it gives plenty of power for me. Good luck! __________________ Clyde65 Rebuild of Clyde http://67-72chevytrucks.com/vboard/s...84#post8338184 69 Aristocrat Lo Liner build http://67-72chevytrucks.com/vboard/s...84#post7561684 *support our troops!*

11-14-2018, 05:35 PM	#7
Nick_c10 Registered User Join Date: Jan 2015 Location: Rapid City SD Posts: 31	Re: LS swap question I’ll keep that in mind Clyde.

11-17-2018, 06:24 PM	#8
tbrown5079 Registered User Join Date: Feb 2007 Location: Blairsville, PA Posts: 301	Re: LS swap question I also agree with Clyde, very happy with my 4.8. All I need! __________________ tbrown's 56 Cameo Build

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.