GMC Truck Forum banner
1 - 20 of 28 Posts

·
SyTy Speed Shop
Joined
·
229 Posts
Discussion Starter · #1 ·
Ok, im looking for a cam to swap into my 2003 5.3 ext cab Silvy. I was browsing the profiles on comps website and found one that is designed for the 4.8/5.3, it is the LSr series and the specs are these,

Part number:54-455-11
Power Band: 1300-6500
LSA: 112
[email protected]: 215/223 Adv Dur 265/273
Lift with stock rocker .604/.610

HYDRAULIC ROLLER-Very strong torque and excellent response. Works best in heavy vehicles, low rpm applications.


My truck has pacesetter LT's and ORY, dynomax ultra flow in place of the stock muffler, all cat back pipe is stock, banks CAI, 05+ efans, blackbear custom tune.

I also have a set of 243 heads that im debating on having shaved down to 59cc chambers and install them along with the cam, and i have a TB LS2 truck intake and 90mm TB im going to install when the cam swap is done, and an underdrive crank pulley.

How well would this cam work, how would it effect drivability in my daily driver? things like MPG and also what converter/gear combo would work best? Im thinking 4.11 gears and a TT3000 converter, but am looking for some feedback.

Thanks
 

·
SyTy Speed Shop
Joined
·
229 Posts
Discussion Starter · #2 ·
Nobody has any thoughts on this cam???
 

·
Registered
Joined
·
768 Posts
I would guess you might want a little looser converter if you could tolerate it. Depending on your tire height, you might want more gear. I have a 28" tire with 3.73's and I think it needs lower gears, i.e. 4.10 or 4.30. That TT3000 is a tight stall from what everyone here says, if you're not sure I'd give Dave a call at Yank, he'd be able to get you what you need. I'm sure someone here with more knowledge will give you some insight. I'm not sure on the lift, maybe the heads you're talking about will utilize that lift, but youll def. need to get some good valvesprings/pushrods. I have a 212/218 .522/.529 on a 114, Z06 springs, and a trailblazer stall and I think I could use more stall, BTW its in a 4.8.
 

·
GMFS slowest truck :read:
Joined
·
5,501 Posts
some will say its too small, some will say its a lil much...get a converter first. then worry about a cam. thats not a bad cam by any means. just may be a lil more than what you want/need. drastically to much? no. slightly more than what id consider "ideal"
 

·
Farmer/Warranty Killer!
Joined
·
203 Posts
not a bad cam. has a good bit of lift but yes you will definitely need a fairly loose stall. my truck is a 6.0l and my cam is 222/228 @.581 .587 and its in a cc nnbs and i need at least a 3600 stall and thats what i opted for. it should go in along with built tranny next wednesday if you want to hold off i can report back with my results?
 

·
Farmer/Warranty Killer!
Joined
·
203 Posts
mpg will go down some. are you running with or w/o cats? and gearing is fine just the stall speed will probably need to be higher with the extra weight of the truck.
 

·
SyTy Speed Shop
Joined
·
229 Posts
Discussion Starter · #7 ·
My truck now has stock 3.42 with the open carrier, im doing the gear/posi swap in the next month or so, and im going to be running a 30" tire, 275/60 17"s. I need to call yank and see what they recommend for the converter, and id like to retain factory towing capacity if possible, as i occasionally pull a 18ft car hauler with an S10 on it, probably close to 6K pounds total give or take.

Let me know how your cam swap turns out.
 

·
Farmer/Warranty Killer!
Joined
·
203 Posts
i did the cam swap about a year ago now. the only thing im doing is building the tranny and updating to a custom built 3600 stall from atlantic coast converter. the only thing about the stock stall that is in it now it is surges bad at stop light and takes way to long to get in the power band of this cam which starts around 2800 rpm or so. give or take. i picked up around 80 rwhp after tune and cam alone. then headers and all bolt ons will help the cam inhale and exhale also. as you know these things need air
towing capacity is about the same other than a little loss down low because of the stock stall and the higher cam power band but cruising and what not it seems to retain the stock feel. but im doing a big motor build next month so im building the trans.
 

·
HOT AIR BALLOON OWNER
Joined
·
14,932 Posts
I wouldn't run it in a vehicle due to the cost of the valve springs you get to shell out for. We've been over this numerous times regarding overlifting the valve, it's some cheap power... and very few at that.

I'd rather use $50 valve springs than a $250 set if I'm stuck with a 4.8 or 5.3

I can build a nitrous kit for $200. It's 1/3 of the way toward headers that'll make more than the 3-7hp huge lift does...

get my drift?
 

·
SyTy Speed Shop
Joined
·
229 Posts
Discussion Starter · #10 ·
I wouldn't run it in a vehicle due to the cost of the valve springs you get to shell out for. We've been over this numerous times regarding overlifting the valve, it's some cheap power... and very few at that.

I'd rather use $50 valve springs than a $250 set if I'm stuck with a 4.8 or 5.3

I can build a nitrous kit for $200. It's 1/3 of the way toward headers that'll make more than the 3-7hp huge lift does...

get my drift?
I see and understand what your saying about over lifting the valve, and agree that huge lift isn't worth the minuscule power gains at high RPM. But with these LS engines, i don't feel that a shade over .600 lift is what you would call excessive or even huge. And a good valve spring set is cheap insurance in my book.

Ive already done headers and exhaust and CAI along with a good tune, Ive don't the NOS thing in the past, and its great while the bottle is full, but the fun runs out pretty fast, and i got tired of having to fill the bottle all the time.

I appreciate the feedback, and im thinking down the road if i swap in a 6.0l this cam will go in and be a nice cam for a stock 6.0l.
 

·
HOT AIR BALLOON OWNER
Joined
·
14,932 Posts
Cost to realized benefit is LOW. i.e. not there. But hey, it's your money.

The heads simply don't flow enough up top to warrant the lift to me. Only reason I have a set of Comp Dual springs is for boost. The increased seat pressure is welcome to keep the boost where it belongs.

$200 is half of what I paid for my LQ4.
 

·
Farmer/Warranty Killer!
Joined
·
203 Posts
this is true. with the lift and flow but what if he happend to get a lq9 that had the 823 casting of the l92 and just went with a little different duration setup on a cam about that size hit manx? just wondering? that would be the later GEN IV because mine has them.
 

·
SyTy Speed Shop
Joined
·
229 Posts
Discussion Starter · #14 ·
Yes i know that the stock heads dont flow all that great, and i know everybody is always against modding the 5.3 and just doing a 6.0L swap, but my truck only has 83K miles, so im now going to do the swap till the 5.3 gives up the ghost, and the cam and springs and other bolt on mods will all change over to the 6.0 down the road. Im considering putting some different heads on, that do flow great at .600 lift.

I called the cam help line yesterday at Comp, and sometimes i dont think those guys know what they are talking about, as the guy recommended the 54-457-11 cam for my truck with the mods i have already done, which specs out at 223/[email protected] with .610/.617 on a 112 LSA, and i said i thought that cam would be very lopey with that much [email protected], but he said it would just barely be noticable over the stock cam. Any thoughts on this.

Also, how about a cam with all the sam specs, just less lift, what is ideal lift for stock 5.3 heads??
 

·
Speed Holes
Joined
·
5,190 Posts
I'll be interested to see what you do with those 243 heads and intake... and if the results amount to anything.

What 5.3 do you have? LM7? What are the casting numbers on your heads?
If you have the L33 it's already got the 799 heads, or basically LS6 heads without the fancy sodium filled valves...


that person you were speaking with on the phone at Comp sounds like they were fucking with you. "Barely noticeable over stock..." wtf?
 

·
Farmer/Warranty Killer!
Joined
·
203 Posts
:worship:yeah that is a pretty decent size cam. my cam sounds VERY NOTICEABLE and its not that big or with as much lift. just for lift sake i would keep it around .585 on the higher side, but that is just me and i know everybody has different opinions. i don't know to very much about 243 heads because i have mainly always had a 6L basis(l92's), but most guys around here find decent power out of somethng like 218/220 and 112 lsa @ around .565 to .570 lift. im sure you can go bigger and be ok with more duration but i would run double springs. to be honest there is only 1 way to find out so if its dead set in your mind then go for it! i would be interested to see the results it might would end up being impressive! you never know till you try
 

·
SyTy Speed Shop
Joined
·
229 Posts
Discussion Starter · #18 ·
I'll be interested to see what you do with those 243 heads and intake... and if the results amount to anything.

What 5.3 do you have? LM7? What are the casting numbers on your heads?
If you have the L33 it's already got the 799 heads, or basically LS6 heads without the fancy sodium filled valves...


that person you were speaking with on the phone at Comp sounds like they were fucking with you. "Barely noticeable over stock..." wtf?
Mine is just the standard 03 lm7 5.3, not the L33. I looked into getting the 243 heads reworked and milled down and its get pretty expensive pretty fast, and was looking at the stage 2.5 heads, that flow well over 300 and seem like a great deal for the money. But ill just stick with stock heads for now.
 

·
Speed Holes
Joined
·
5,190 Posts
Mine is just the standard 03 lm7 5.3, not the L33. I looked into getting the 243 heads reworked and milled down and its get pretty expensive pretty fast, and was looking at the stage 2.5 heads, that flow well over 300 and seem like a great deal for the money. But ill just stick with stock heads for now.
yeah, same here. One reason I was curious to see if you'd follow through with it.
Are you talking about those PRC heads?
 
1 - 20 of 28 Posts
Top