243 Heads on my LQ4
Thread Starter
Registered User
Joined: Jun 2026
Posts: 1
Likes: 1
243 Heads on my LQ4 Hello folks , Daniel here
Lots of questions coming yall way from a LS newbie. Been reading up roughly 4 years on them but will wanna double check many things to make sure I知 not overlooking anything. So far I知 thinking COMP CAM Thumper master kit, set of headers(Not amazon)😂
TBSS intake, new high volume standard pressure oil pump, flow cooler high flow water pump, 4 corner steam kit, prw trunnion upgrade
Catch can
I haven稚 opened up the 6.0 yet to know what the pistons, rings and cylinders look like. It has 250k miles. At minimum new rings. Maybe a hone and oversized rings. We値l see
I致e recently picked up a 2010 5.3 with 243 heads.
My question is will the 243 heads work with this block? 7 layer .055 head gasket. From what I gather they will 100% work. Just want to clarify.
Also after removing the 243 heads and inspecting them .. doesn稚 look like there is a whole lot of material to be ported out like I致e witnessed in other heads in the past(Not LS). Maybe cleaning up a few ridges and polishing. What痴 yall experience with these ? Would it be worth the money sending them to a machine shop with CNC capabilities to port and polish ? Or just take my time a clean them up myself by hand.
Lots of questions coming yall way from a LS newbie. Been reading up roughly 4 years on them but will wanna double check many things to make sure I知 not overlooking anything. So far I知 thinking COMP CAM Thumper master kit, set of headers(Not amazon)😂
TBSS intake, new high volume standard pressure oil pump, flow cooler high flow water pump, 4 corner steam kit, prw trunnion upgrade
Catch can
I haven稚 opened up the 6.0 yet to know what the pistons, rings and cylinders look like. It has 250k miles. At minimum new rings. Maybe a hone and oversized rings. We値l see
I致e recently picked up a 2010 5.3 with 243 heads.
My question is will the 243 heads work with this block? 7 layer .055 head gasket. From what I gather they will 100% work. Just want to clarify.
Also after removing the 243 heads and inspecting them .. doesn稚 look like there is a whole lot of material to be ported out like I致e witnessed in other heads in the past(Not LS). Maybe cleaning up a few ridges and polishing. What痴 yall experience with these ? Would it be worth the money sending them to a machine shop with CNC capabilities to port and polish ? Or just take my time a clean them up myself by hand.
Those heads will for sure work on your LQ4. I run 799 heads (same thing as 243) on my LQ4 block. I also have gen 4 rods and flat top pistons, so my compression is around 11.0:1, same thing as a LS2. Now, porting them will help with power but worth it? Eh, if you're not trying to squeeze every ounce of horsepower out of your set up then it's hard to say if it's worth the money. But short answer, it will make more horsepower, maybe not a ton more. My 799 heads are ported but my buddy owns the shop and ported them for free, so completely worth it to me in my case. Big turbo set up, I want ALL the air these heads could give me.
Thread Starter
Registered User
Joined: Jun 2026
Posts: 1
Likes: 1
Those heads will for sure work on your LQ4. I run 799 heads (same thing as 243) on my LQ4 block. I also have gen 4 rods and flat top pistons, so my compression is around 11.0:1, same thing as a LS2. Now, porting them will help with power but worth it? Eh, if you're not trying to squeeze every ounce of horsepower out of your set up then it's hard to say if it's worth the money. But short answer, it will make more horsepower, maybe not a ton more. My 799 heads are ported but my buddy owns the shop and ported them for free, so completely worth it to me in my case. Big turbo set up, I want ALL the air these heads could give me.
TECH Addict
Joined: Dec 2017
Posts: 2,197
Likes: 980
Yup, it'll all bolt right up. They'll give you a bit of compression bump, not quite to the LQ9 level, butt most of the way, which should help.
Those cams aren't known for making power. They're for people in the square-inches-of-chrome type contests that want 9-yr-old kids to ooooooh and aaaaaah all over it in parking lots. All they give you, is "sound". IOW, monkey-spank. Particularly bad choice for a truck, as sounds like what you've got maybe. Quite possibly will slow the vehicle down from stock.
Tell us what this is in and what you intend to do with it and maybe we can pick you out something better.
Those cams aren't known for making power. They're for people in the square-inches-of-chrome type contests that want 9-yr-old kids to ooooooh and aaaaaah all over it in parking lots. All they give you, is "sound". IOW, monkey-spank. Particularly bad choice for a truck, as sounds like what you've got maybe. Quite possibly will slow the vehicle down from stock.
Tell us what this is in and what you intend to do with it and maybe we can pick you out something better.
Last edited by RB04Av; Yesterday at 11:44 AM.
Thread Starter
Registered User
Joined: Jun 2026
Posts: 1
Likes: 1
Yup, it'll all bolt right up. They'll give you a bit of compression bump, not quite to the LQ9 level, butt most of the way, which should help.
Those cams aren't known for making power. They're for people in the square-inches-of-chrome type contests that want 9-yr-old kids to ooooooh and aaaaaah all over it in parking lots. All they give you, is "sound". IOW, monkey-spank. Particularly bad choice for a truck, as sounds like what you've got maybe. Quite possibly will slow the vehicle down from stock.
Tell us what this is in and what you intend to do with it and maybe we can pick you out something better.
Those cams aren't known for making power. They're for people in the square-inches-of-chrome type contests that want 9-yr-old kids to ooooooh and aaaaaah all over it in parking lots. All they give you, is "sound". IOW, monkey-spank. Particularly bad choice for a truck, as sounds like what you've got maybe. Quite possibly will slow the vehicle down from stock.
Tell us what this is in and what you intend to do with it and maybe we can pick you out something better.
Yes I have a 2001 HD. Eventually I壇 like to dabble at the tracks but currently raising 4 youngsters. It痴 not in the bank account to do both. Just looking for more horse power without breaking the bank. My girls are finding it interesting that daddy痴 working on a truck for fun. Not just always fixing family vehicles lol They致e actually been watching me tare down the 5.3 that I acquired and asking questions!!
I pull a boat from time to time but mostly want to see their eyes light up when I mash the throttle like I did when I was younger when my brother took me for a spin in his 60 Chevy truck
Trending Topics
11 Second Club
Joined: Mar 2012
Posts: 164
Likes: 16
From: fbg, tx
I put a set of 243s on an lq9 out of a cadillac with 200k miles good thing it was a cadillac that engine was so well taken care off.
it made a lot of power the increase in compression is worth it might be only 15 hp but its 15hp thruout the rpm range itll pull better than a truck with less compression and a cam.
Mine just had what i said, shorty header, SS exhaust and a tune i did myself and it would smoke cammed 5.3s kid had to use a 100 shot of nitrous to pull on me on the last run. Also it would spin all 4 wheels off the line. With stock converter.
it made a lot of power the increase in compression is worth it might be only 15 hp but its 15hp thruout the rpm range itll pull better than a truck with less compression and a cam.
Mine just had what i said, shorty header, SS exhaust and a tune i did myself and it would smoke cammed 5.3s kid had to use a 100 shot of nitrous to pull on me on the last run. Also it would spin all 4 wheels off the line. With stock converter.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?
Pouria Savadkouei
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
