5.3 engine upgrades
Thread Starter
Teching In
Joined: Mar 2020
Posts: 2
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5.3 engine upgrades So I have a 2003 LM7 I am rebuilding for my 1995 GMC K2500. Im wondering if there is a list (I have looked and not found one in one place) for good upgrades when rebuilding. Here is what I have so far by hunting and getting bits here and there. Now keep in mind I am not building a powerhouse, I am looking for a slight bump but mostly a super reliable engine for a daily driver.
Outer than the obvious things when rebuilding (bearings, oil pump, new lifter keepers, seals, etc...)
*Upgrade replacement parts for the LM7 engine*
- LS2 timing chain
- Bronze rocker bushing trunion upgrade (to loose the needle bearings)
- Oil pickup tube hold down (for both bolts)
- Four corner steam vents
- Mild cam upgrade w/new valve springs (like the Texas speed low lift truck cam kit)
- 4.8L flat top pistons (to bump a little compression, moves it from 9.5 to about 10.3)
- Timing chain guide bracket and guide (to stabilize the timing chain between shifts)
- LS7 lifters
- Custom tune
This is what I have gathered as UPGRADES for a mild stockish build (again, not really looking for lots of performance). Keep in mind I am am working with a non-VVT engine, if someone is running a VVT engine there is more stuff, I know. I dont wanna build another engine for this truck for a very long time, if at all. I know the trunion bushing upgrade is not really needed for mild performance, but its not that much more than the replacement bearings so its kinda worth it. This is for the engine only, not the exhaust, or transmission, or anything else. Does anyone have any advice on things to add or change?
I hope to build a "Master list" of sorts for the builders out there that want a good reliable engine for a stock car/truck or engine swap car/truck to reference in one place. I know most builds are different depending on desires, but there should be a baseline. "If your going to spend the money, you should at least do this..." kinda thing. I am trying to stay away from aftermarket parts (like aluminum roller rockers) so it can stay budget friendly, anyone can just throw a ton of money at something to make it happen, but not everyone can afford that. Let me know what you all think....
P.S. I can supply the part numbers of what I am using if anyone is interested (I might add those later anyway)
Outer than the obvious things when rebuilding (bearings, oil pump, new lifter keepers, seals, etc...)
*Upgrade replacement parts for the LM7 engine*
- LS2 timing chain
- Bronze rocker bushing trunion upgrade (to loose the needle bearings)
- Oil pickup tube hold down (for both bolts)
- Four corner steam vents
- Mild cam upgrade w/new valve springs (like the Texas speed low lift truck cam kit)
- 4.8L flat top pistons (to bump a little compression, moves it from 9.5 to about 10.3)
- Timing chain guide bracket and guide (to stabilize the timing chain between shifts)
- LS7 lifters
- Custom tune
This is what I have gathered as UPGRADES for a mild stockish build (again, not really looking for lots of performance). Keep in mind I am am working with a non-VVT engine, if someone is running a VVT engine there is more stuff, I know. I dont wanna build another engine for this truck for a very long time, if at all. I know the trunion bushing upgrade is not really needed for mild performance, but its not that much more than the replacement bearings so its kinda worth it. This is for the engine only, not the exhaust, or transmission, or anything else. Does anyone have any advice on things to add or change?
I hope to build a "Master list" of sorts for the builders out there that want a good reliable engine for a stock car/truck or engine swap car/truck to reference in one place. I know most builds are different depending on desires, but there should be a baseline. "If your going to spend the money, you should at least do this..." kinda thing. I am trying to stay away from aftermarket parts (like aluminum roller rockers) so it can stay budget friendly, anyone can just throw a ton of money at something to make it happen, but not everyone can afford that. Let me know what you all think....
P.S. I can supply the part numbers of what I am using if anyone is interested (I might add those later anyway)
TECH Senior Member
Joined: Jun 2016
Posts: 22,291
Likes: 3,616
From: Central Cal.
Don't forget new plastic lifter trays. Summit has a kit that includes LS7 lifters, trays and tray bolts.
You might also get a new cam thrust plate. It's what holds the cam in, and they do wear.
You might also get a new cam thrust plate. It's what holds the cam in, and they do wear.
So I have a 2003 LM7 I am rebuilding for my 1995 GMC K2500. Im wondering if there is a list (I have looked and not found one in one place) for good upgrades when rebuilding. Here is what I have so far by hunting and getting bits here and there. Now keep in mind I am not building a powerhouse, I am looking for a slight bump but mostly a super reliable engine for a daily driver.
Outer than the obvious things when rebuilding (bearings, oil pump, new lifter keepers, seals, etc...)
*Upgrade replacement parts for the LM7 engine*
- LS2 timing chain
- Bronze rocker bushing trunion upgrade (to loose the needle bearings)
- Oil pickup tube hold down (for both bolts)
- Four corner steam vents
- Mild cam upgrade w/new valve springs (like the Texas speed low lift truck cam kit)
- 4.8L flat top pistons (to bump a little compression, moves it from 9.5 to about 10.3)
- Timing chain guide bracket and guide (to stabilize the timing chain between shifts)
- LS7 lifters
- Custom tune
)
Outer than the obvious things when rebuilding (bearings, oil pump, new lifter keepers, seals, etc...)
*Upgrade replacement parts for the LM7 engine*
- LS2 timing chain
- Bronze rocker bushing trunion upgrade (to loose the needle bearings)
- Oil pickup tube hold down (for both bolts)
- Four corner steam vents
- Mild cam upgrade w/new valve springs (like the Texas speed low lift truck cam kit)
- 4.8L flat top pistons (to bump a little compression, moves it from 9.5 to about 10.3)
- Timing chain guide bracket and guide (to stabilize the timing chain between shifts)
- LS7 lifters
- Custom tune
)
Oil pick up hold down is not really necessary.
Four corner steam vents are not necessary.
Timing chain guide bracket, requires you to drill and tap holes in the block. A 1999 to 2006 block anyway.
Cam kit, pistons, and everything else stock replacement is fine for reliability.
TECH Fanatic
Joined: Dec 2017
Posts: 1,467
Likes: 265
From: Bossier City, Louisiana
Hello,
You might consider boring your 5.3 iron block out to 5.7 liters. There's generally enough meat in an iron 5.3 to do this as long as your machinist measures for casting core shift. With there only being pennies difference in price between these pistons to go big, I'd probably do it if I was you. It would require a very minor change in cylinder volume within your tune but that's easy.
There's no replacement for more displacement.
Rick
You might consider boring your 5.3 iron block out to 5.7 liters. There's generally enough meat in an iron 5.3 to do this as long as your machinist measures for casting core shift. With there only being pennies difference in price between these pistons to go big, I'd probably do it if I was you. It would require a very minor change in cylinder volume within your tune but that's easy.
There's no replacement for more displacement.
Rick
Thread Starter
Teching In
Joined: Mar 2020
Posts: 2
Likes: 0
The stock rockers are fine.
Oil pick up hold down is not really necessary.
Four corner steam vents are not necessary.
Timing chain guide bracket, requires you to drill and tap holes in the block. A 1999 to 2006 block anyway.
Cam kit, pistons, and everything else stock replacement is fine for reliability.
Oil pick up hold down is not really necessary.
Four corner steam vents are not necessary.
Timing chain guide bracket, requires you to drill and tap holes in the block. A 1999 to 2006 block anyway.
Cam kit, pistons, and everything else stock replacement is fine for reliability.
Your right, those are overkill, but I like to be cautious when im spending that kinda money and time, I am willing to spend a little more of the added insurance. There is a retrofit timing chain tensioner kit that dosnt require the drilling of the block. Here: https://www.summitracing.com/parts/tfs-k30675600
Your right, those are overkill, but I like to be cautious when im spending that kinda money and time, I am willing to spend a little more of the added insurance. There is a retrofit timing chain tensioner kit that dosnt require the drilling of the block. Here: https://www.summitracing.com/parts/tfs-k30675600
If you're dead set on something you might not need a second opinion.
TECH Addict
Joined: Dec 2017
Posts: 2,180
Likes: 969
Best upgrade you can do to a LM7, is a LQ9 long block. Pay what it takes to get the most pristine one you can find. Preferably out of a low-mileage Escalade that was owned by some middle-aged aerobics / Zumba / Yoga queen. Pay what it takes to get THE BEST one you can find.
DO NOT mess with pistons, bearings, rings, or any of that, in your LM7.
Took me all of about 10 minutes to drill & tap the holes in a LQ9 block to install a timing chain tensioner. More of a stabilizer, really, than a "tensioner". I would certainly not consider it an ordeal; hardly even a stumbling block.
DO NOT mess with pistons, bearings, rings, or any of that, in your LM7.
Took me all of about 10 minutes to drill & tap the holes in a LQ9 block to install a timing chain tensioner. More of a stabilizer, really, than a "tensioner". I would certainly not consider it an ordeal; hardly even a stumbling block.
