LS with manual 3 speed

[richard2717]

I am wondering if a 4.8 or 5.3 LS will bolt up and work with the 3 speed on the tree in my 69 C10? Right now I am working with a tired 307 and have this thought of the newer LS engine but retaining the 3ott. I know it is not popular, but I would also want to put a carb on the ls instead of running the FI. Trying to stay away from computers on the truck.

[Getter-Done]

Here is the first/Closest thing doing something like this swap you are thinking of.

Link: https://www.motortrend.com/how-to/ma...eed-ls-engine/

You could be the 1st one putting a 3 Speed behind one.

I am sure it can be done.

Probably a lot of Measuring and fabrication involved.

You can be a Trend setter.

[richard2717]

Dwayne
Thanks for that link. Looks like it has all the info needed. Basically the hardest part will be to fab up a bracket for the Z bar to go over to the block which should not be a huge deal for me. I don't plan to hot rod the truck at all so this might work for me. Now to find a motor, I would hate to have to snatch the one out of my 02 gmc

[HO455]

Here's some information to put a Muncie 4 speed behind an LS which should apply to the 3 speed too.

https://www.speedwaymotors.com/the-t...rts-list/30449

https://www.motortrend.com/how-to/ma...eed-ls-engine/

https://ls1tech.com/forums/conversio...-ls-motor.html

And carbureted LS

https://ls1tech.com/how-tos/slidesho...8#2-carburetor

https://www.motortrend.com/how-to/wa...t-1967-camaro/

https://paceperformance.com/c-106384...manifolds.html

[richard2717]

Originally Posted by HO455

Here's some information to put a Muncie 4 speed behind an LS which should apply to the 3 speed too.

https://www.speedwaymotors.com/the-t...rts-list/30449

https://www.motortrend.com/how-to/ma...eed-ls-engine/

https://ls1tech.com/forums/conversio...-ls-motor.html

And carbureted LS

https://ls1tech.com/how-tos/slidesho...8#2-carburetor

https://www.motortrend.com/how-to/wa...t-1967-camaro/

https://paceperformance.com/c-106384...manifolds.html

Thanks, looks like I got plenty of reading up to do. I do think this is the route I am gonna take if this 307 don't work out. I have a couple decent 350 engines but they have been sitting so rather than dump money in them I kinda like this idea

[LS short box]

My .02? You will be money ahead just buying a rebuilt long block from someone like Blue Print. LS wise you will still need a engine controller of some type like MSD. Not cheap.
And this coming from a dedicated LS swap guy.

[mongocanfly]

I wouldn't put a carb on a LS if I had a truckload of em..
I used to be the same way..don't want the electronics..
But after running LSs for many yrs now , I'm sold on the fuel inj..

[hewittca]

I was in the same position as you last year when my original engine blew up. I wanted to retain the 3 OTT, or at least a manual trans. After some deliberation I ended up ditching the 3 speed and going with a junkyard NV3500. It was a fairly simple union between the trans and my 5.3 LS. I didn't do anything internal to the trans. Maybe I got lucky, but it drives and shifts great. Just thought I'd put that out there in case the 3 OTT option doesn't work for you. As for the electronics, these things are fairly simple when setup as stand alone and also quite reliable. It is definitely nice to just jump in and go in any conditions, with decent fuel mileage as an added bonus!

[richard2717]

so after reading quite a bit along with your comments here I don't think the carb helps with anything. As stated I still need some kind of controller for the coil packs, so if I gotta do that I might just as well do the stand alone harness that will allow me to run the FI. My son's buddy supposedly has a wrecked truck with low mileage 5.3 that can hear run (my son not me lol) for $600. Trying to find out what year/ version it is now. Am i understanding correctly that the 01-02 models are better for this type of conversion? Thinking I should stick with cable driven.

Another question is am I still able to run the factory dash cluster or will the gauges not work with the ls senders? I read something about still having to have an inline vss something plugged into the harness with the manual transmission to keep it from stalling?

[LS short box]

I believe all truck LS's came with DBW throttle bodies. Camaros came with DBC.
Nothing wrong with either. I've used both with good results.
Because I'm no electrical wiz so I buy the ECM and the engine harness as a kit. I like and use Howell and Speartech. Per your engine specs they will put in a base tune to get you started. Both have good tech service if you have an issue. I would not buy a Ebay ECM/harness made off shore.
Gauges wise I've always used Auto Meter. Your stock speedo is cable driven and if your "new" tranny is the cable type you are good. Gas gauge can stay as is. Oil pressure sender can be adapted to the LS engine. Coolant sender could be adapted but I'm not sure. Can't say on the voltmeter.
The key to a good LS swap is a good harness and good grounds.

[mongocanfly]

The only thing the ecm needs to see is water temp, that uses the LS sender on drivers head
use a sender adapter for oil pressure, and what I did for water temp was drill and tap pass side head for that sender
You don't need vss with a manual, I just folded that harness plug back into the wire loom..
The earlier LS engines won't have all the crap that everybody deletes..
If the engine is dbw it can be swapped to dbc by simply changing the throttle..
But you need to know all about your setup before you by a harness..
And also whoever tunes your ecm will need to know of any changes

[richard2717]

Originally Posted by LS short box

I believe all truck LS's came with DBW throttle bodies. Camaros came with DBC.
Nothing wrong with either. I've used both with good results.
Because I'm no electrical wiz so I buy the ECM and the engine harness as a kit. I like and use Howell and Speartech. Per your engine specs they will put in a base tune to get you started. Both have good tech service if you have an issue. I would not buy a Ebay ECM/harness made off shore.
Gauges wise I've always used Auto Meter. Your stock speedo is cable driven and if your "new" tranny is the cable type you are good. Gas gauge can stay as is. Oil pressure sender can be adapted to the LS engine. Coolant sender could be adapted but I'm not sure. Can't say on the voltmeter.
The key to a good LS swap is a good harness and good grounds.

My 02 gmc sierra 5.3 is cable operated. I think after all the reading I may pass on doing this project and just go for getting the ole 307 tuned in a bit better. I am way out of my comfort zone on this unless I can find someone local to help with it. I am still going to keep looking for a donor truck or tahoe for "just in case" but I don't want this to become a long drawn out project like a couple others I have.Thanks to all for the insight on my questions.

[HO455]

I'll suggest going with a set of Vortex heads on the 307 or step up a bit and put a 350 Vortex engine in. Much better design of the head and it will be easy to go carbureted and bolt your transmission up.