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-   -   Updating a LM7 for transplant (https://67-72chevytrucks.com/vboard/showthread.php?t=737682)

Nima 05-11-2017 09:34 PM

Updating a LM7 for transplant
 
Hi: I bought a 2001 LM7 with 107000 miles on it to drop in place of the tired 350. I was wondering if there is any maintenance update that I should do before dropping the engine? Any seals or gasket that these engine might be prone to fail?
Also is there a mild and easy performance upgrade that I can do without affecting the reliability of the engine considering it has 107000 miles on it? Cam upgrade for example?
It is going to be daily driver, nothing wild but we all enjoy a little more power.
Thanks,

mongocanfly 05-11-2017 10:05 PM

Re: Updating a LM7 for transplant
 
My lq9 had 107k on it when I put it in..I didn't worry bout it..these LS engines seem to run forever with little maintenance...some will change small items while its in the floor just for piece of mind..what are you putting it in?..I'm sure you've done your research but if not I doubt its just gonna drop in whatever you've got..what trans are you gonna put behind it?

Nima 05-12-2017 12:30 AM

Re: Updating a LM7 for transplant
 
I have been reading a lot about them. This is going to go to 79 Camaro with a rebuild TH350 with a shift kit. I also know that I need adaptor to mate engine and tranny together.
I have been reading these engine improve a lot with cam upgrade and simple off the shelves ad ons. I have never done any cam swap.

truckster 05-12-2017 12:39 AM

Re: Updating a LM7 for transplant
 
I don't have any specific recommendations for you, but one of the nice things about roller cams is that you don't have to worry about breaking them in, so that might make it a little more comfortable for you to take on.

mongocanfly 05-12-2017 12:56 AM

Re: Updating a LM7 for transplant
 
Cam change in a ls is fairly simple...but seeing as to how you've never done it before get someone that has to give you a hand..they make hp easily with very little..a good cam and headers with a good dyno tune is awsome...check out btr cams..they have stage 1, 2, 3 setups..I'd recommend bying the swap kit if you go that route..check out utube for how they sound...I'm fixing to dump a stage 3 in my ls3..consider swapping the oil pump and a few gaskets and you will be good to go..but whatever you decide put it on a dyno..

LeesTruk 05-12-2017 06:23 AM

Re: Updating a LM7 for transplant
 
I put an LM7 into my '80 C10 ('05 Tahoe engine, 139K miles) and used the BTR stg.1 cam, valve springs, and rocker arm bearing upgrade. While I was in the engine I changed the timing set and oil pump just for peace-of-mind. I also used an I6 Trailblazer torque convertor (2200 stall). Truck is very docile around town, but has really good response and power for when the need (?) arises. It also gets surprisingly good fuel economy for being a toy, if you can keep from getting too "eager' with the gas pedal ( restraint is an option ). Haven't seen a dyno yet, and I know there is more power on the table, but the truck runs so good as it is...

Jstock85 05-12-2017 10:11 AM

Re: Updating a LM7 for transplant
 
working on a 4.8 with a th350. i just picked up oil pump, belt and several gaskets but like mono said that is mainly for my "peace of mind" while I have it out.

Nima 05-12-2017 03:11 PM

Re: Updating a LM7 for transplant
 
Thanks guys. I have read that these engines are build to last. Also I have read since these are truck/suv engines and built with a high end torque, iron block with good flow stock aluminum heads, they respond well with a simple upgrades such as cam swap and a set of headers for use in muscle cars.

71cheyennesuperlongb 05-12-2017 08:27 PM

Re: Updating a LM7 for transplant
 
Just be sure If you pull the oil pump there is a certian procedure to reinstall such as shimming the pump. You just cant bolt it on and go . Afew motors have been hurt by not doing it properly.

truckdude239 05-13-2017 11:23 AM

Re: Updating a LM7 for transplant
 
best thing i can say is couple hunred in gaskets will its out go head and change the rear main seal, intake vavle cover gakets knock sensors and knonk sensor harness while the intake is off , my 4.8 the only leaks i have is the rear main and intake leaking i just stuck the thing in without changing anything

BossHogg69 05-14-2017 03:33 PM

Re: Updating a LM7 for transplant
 
First thing I'd do is pull the valve covers and make sure it doesn't have Castech heads on it before spending a bunch of money on go fast parts.

https://www.jalopyjournal.com/forum/...ngines.933574/

http://speedtalk.com/forum/viewtopic.php?f=1&t=28519

http://www.gminsidenews.com/forums/f...r-heads-83436/

WELL documented problem and usually only shows up after 100k miles or so. My '05 GMC 5.3 started giving me issues after about 140k, smoking, using antifreeze with no visible leaks, then started running hot and sludgy oil.

Anyway, I had previously installed a Comp Cams LSR 265 cam, long tube headers, Blackbear custom tune and a Yank 2600 stall converter - which really woke things up. After both of the heads cracked, I installed a set of Texas Speed PRC stage 2.5 heads to go along with the other stuff I already had and the thing came alive.

93Polo 05-14-2017 03:47 PM

Re: Updating a LM7 for transplant
 
Quote:

Originally Posted by truckdude239 (Post 7941787)
best thing i can say is couple hunred in gaskets will its out go head and change the rear main seal, intake vavle cover gakets knock sensors and knonk sensor harness while the intake is off , my 4.8 the only leaks i have is the rear main and intake leaking i just stuck the thing in without changing anything

I have owned a few LS powered cars, heads and cam C5s, and my '01 2500HD which has 170k on it. I would do front / rear main seals and cover gaskets, and an oil pan gasket. It may cost less to buy a rear cover with gasket installed than replacing the gasket. I just had the oil pan, rear cover rear main, and the oil cooler adapter gaskets replaced on my 2500.

CamMotion has drop in cams for the 5.3s which have given solid results with very little down side. If you want to be more aggressive the LS world has plenty of options. I would also do a Straub or CHE trunion upgrade. We just did the Straub trunion upgrade on a friend's C5, great customer service, good product. If you do a cam I would do a timing chain, lifters, push rods, and an oil pump.

https://ls1tech.com/forums/dynamomet...hp-22rwtq.html

Nima 05-14-2017 11:46 PM

Re: Updating a LM7 for transplant
 
Quote:

Originally Posted by BossHogg69 (Post 7942504)
First thing I'd do is pull the valve covers and make sure it doesn't have Castech heads on it before spending a bunch of money on go fast parts.

https://www.jalopyjournal.com/forum/...ngines.933574/

http://speedtalk.com/forum/viewtopic.php?f=1&t=28519

http://www.gminsidenews.com/forums/f...r-heads-83436/

WELL documented problem and usually only shows up after 100k miles or so. My '05 GMC 5.3 started giving me issues after about 140k, smoking, using antifreeze with no visible leaks, then started running hot and sludgy oil.

Anyway, I had previously installed a Comp Cams LSR 265 cam, long tube headers, Blackbear custom tune and a Yank 2600 stall converter - which really woke things up. After both of the heads cracked, I installed a set of Texas Speed PRC stage 2.5 heads to go along with the other stuff I already had and the thing came alive.

Thanks, I will check it out when the engine is delivered. Meanwhile I keep my fingers crossed! It is funny that you never know these things about cars until you buy them!

Tom 05-15-2017 06:58 PM

Re: Updating a LM7 for transplant
 
With 107k I'd replace every gasket on the thing since its out and disconnected.

Jstock85 05-17-2017 01:27 PM

Re: Updating a LM7 for transplant
 
Quote:

Originally Posted by 71cheyennesuperlongb (Post 7941450)
Just be sure If you pull the oil pump there is a certian procedure to reinstall such as shimming the pump. You just cant bolt it on and go . Afew motors have been hurt by not doing it properly.

I was under the impression that the shims are for double roller chains? Is there something that needs to be done to stock set ups?


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