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Hey guys, new to the lovely world of LSX haha! I've had a few Foxes and currently running a 1995 GT. I have an 89 Trans Am that I would like to swap next year.
Finishing up a new suspension, (lots of UMI, Koni Yellows etc etc) C5 front brakes and PBR rears.
Over the past few months I've been reading/researching a lot. I was hoping some of you seasoned LSX pros can steer me in the right direction.
This is not a heavy HP build. Not chasing a number on a dyno but 380-400 at wheels would be fun lol!
I drive my car often so stock like driveability is needed.
The car will have a rebuilt 4L60E and running a 7.5 with 3.42s.
My current list of parts/combo is:
LQ4 shortblock
853 heads (were rebuilt and given to me for next to nothing) I want to have the CC checked to see if they have been milled. They are in great shape and came off a good friend's car.
TBSS Intake -- Will get a 92mm throttle body.
00-02 F-Body manifolds -- Using cat converters is a MUST! and I don't want to deal with any of the usual header "annoyances"
Where I need assistance is cam selection. I don't want a choppy idle, prefer something stock like. I was leaning towards an LS6 cam but I can get something aftermarket that is quiet, long lasting and can make better power I am down,
Don't want any additional valvetrain noise. Due to using manifolds something that would be optimized for them. What's even more important for me is no exhaust "fume" smell. I'm very sensitive to this. Another reason for cats.
I also thought of getting 243s or 799 and having them CNCd by one of the usual players. My good friend who will be doing most of the swap for me tells me get the heads if I want but run them as is.
His reasoning to leave them stock because I'm a ***** (hahahha) running manifolds and want a mild cam so there is no point in the CNC job.
Thanks for reading and looking forward to your input!
Honestly, reading what you're looking for, that stock LS6 Cam might just be the ticket. Dirt cheap, OE sound. If not that, look at something in the BTR stage 1 range of duration and lift.
Honestly, reading what you're looking for, that stock LS6 Cam might just be the ticket. Dirt cheap, OE sound. If not that, look at something in the BTR stage 1 range of duration and lift.
This is not a heavy HP build. Not chasing a number on a dyno but 380-400 at wheels would be fun lol!
I drive my car often so stock like driveability is needed.
The car will have a rebuilt 4L60E and running a 7.5 with 3.42s.
What torque converter will you be using? A high quality torque converter with a good stall will do more for the fun factor than just about anything. Something like a tight 2,800 to 3,600 rpm stall Yank SS, Precision Industries Vigilante etc.
My current list of parts/combo is:
LQ4 shortblock
853 heads (were rebuilt and given to me for next to nothing) I want to have the CC checked to see if they have been milled. They are in great shape and came off a good friend's car.
Set of 799's or 243's would really rock on that engine.
TBSS Intake -- Will get a 92mm throttle body.
Great choice, it flows very well.
00-02 F-Body manifolds -- Using cat converters is a MUST! and I don't want to deal with any of the usual header "annoyances"
If required for emissions testing etc OK, one has to do what one has to do. I'd look for a set of LS7 exhaust manifolds if stuck with manifolds. They are much better than the F-body manifolds.
There really isn't a down side to a good set of headers. Have had several LS's with headers and it was always worth the cost & minor annoyances that can occur.
Have seen fbody headers choke 40+ whp off of a decent heads & cam LS1 before in a 99 T/A M6. The 98-99 manifolds are worse than the 00-02's but the 00-02's aren't all that. Anyway his car had a sweet little low lift 216/220 Comp Cam that behaved practically like stock and an excellent set of MORE Performance Stage 2 853 heads...dyno'd ~360 whp. Later car owner stepped up to a set of 1 3/4 inch headers and a returned and the cam made ~400+ whp, IIRC was 406 whp peak and kept its practically stock manners.
Where I need assistance is cam selection. I don't want a choppy idle, prefer something stock like. I was leaning towards an LS6 cam but I can get something aftermarket that is quiet, long lasting and can make better power I am down,
Don't want any additional valvetrain noise. Due to using manifolds something that would be optimized for them. What's even more important for me is no exhaust "fume" smell. I'm very sensitive to this. Another reason for cats.
Excellent reason for a good tune as smell is as much a function of tuning as it is cats a lot of the time. I would waste time on an LS6 cam swap personally.
Bare minimum would be the well proven LPE GT2-3 cam 207/220 duration @ .050 lift -.571/.578 lift with 1.7 rocker 118.5 CL
Other choice with good manners that should work very well Summit's SUM-8715 Stage 1 Pro LS Ghost Cam. 222/233 115+3, .600/.575 Lift, Ultimate Stealth Cam
There are also lots of excellent choices inbetween these two to tailor for your ideal combination.
I also thought of getting 243s or 799 and having them CNCd by one of the usual players. My good friend who will be doing most of the swap for me tells me get the heads if I want but run them as is.
Might as well and do it once and do it right
His reasoning to leave them stock because I'm a ***** (hahahha) running manifolds and want a mild cam so there is no point in the CNC job.
Thanks for reading and looking forward to your input!
Better valve job and cleaning up the bowl area will really help without having to do a full CNC. Of course appropriate vavles spring kit & new valve seals.
Unless you're endlessly stuck in traffic or sitting at stop lights or spending a half hour waiting in line for ☕️ coffee at Starbucks each morning, I'd get a quality set of long tube headers as the smell & hassle will be minimal. That's my experience driving with long tube headers & no cats since 1983.
What torque converter will you be using? A high quality torque converter with a good stall will do more for the fun factor than just about anything. Something like a tight 2,800 to 3,600 rpm stall Yank SS, Precision Industries Vigilante etc.
Set of 799's or 243's would really rock on that engine.
Great choice, it flows very well.
If required for emissions testing etc OK, one has to do what one has to do. I'd look for a set of LS7 exhaust manifolds if stuck with manifolds. They are much better than the F-body manifolds.
There really isn't a down side to a good set of headers. Have had several LS's with headers and it was always worth the cost & minor annoyances that can occur.
Have seen fbody headers choke 40+ whp off of a decent heads & cam LS1 before in a 99 T/A M6. The 98-99 manifolds are worse than the 00-02's but the 00-02's aren't all that. Anyway his car had a sweet little low lift 216/220 Comp Cam that behaved practically like stock and an excellent set of MORE Performance Stage 2 853 heads...dyno'd ~360 whp. Later car owner stepped up to a set of 1 3/4 inch headers and a returned and the cam made ~400+ whp, IIRC was 406 whp peak and kept its practically stock manners.
Excellent reason for a good tune as smell is as much a function of tuning as it is cats a lot of the time. I would waste time on an LS6 cam swap personally.
Bare minimum would be the well proven LPE GT2-3 cam 207/220 duration @ .050 lift -.571/.578 lift with 1.7 rocker 118.5 CL
Other choice with good manners that should work very well Summit's SUM-8715 Stage 1 Pro LS Ghost Cam. 222/233 115+3, .600/.575 Lift, Ultimate Stealth Cam
There are also lots of excellent choices inbetween these two to tailor for your ideal combination.
Might as well and do it once and do it right
Better valve job and cleaning up the bowl area will really help without having to do a full CNC. Of course appropriate vavles spring kit & new valve seals.
Unless you're endlessly stuck in traffic or sitting at stop lights or spending a half hour waiting in line for ☕️ coffee at Starbucks each morning, I'd get a quality set of long tube headers as the smell & hassle will be minimal. That's my experience driving with long tube headers & no cats since 1983.
Best of wishes with the project!
Great advice! I would also add to the cam list - pretty much any of the stage 1 or 2 truck cams that are available. Often they are in the 212-220 range on intake duration and still make very good vacuum and driving manners, because they are designed to still work well at low RPM.
What torque converter will you be using? A high quality torque converter with a good stall will do more for the fun factor than just about anything. Something like a tight 2,800 to 3,600 rpm stall Yank SS, Precision Industries Vigilante etc.
Set of 799's or 243's would really rock on that engine.
Great choice, it flows very well.
If required for emissions testing etc OK, one has to do what one has to do. I'd look for a set of LS7 exhaust manifolds if stuck with manifolds. They are much better than the F-body manifolds.
There really isn't a down side to a good set of headers. Have had several LS's with headers and it was always worth the cost & minor annoyances that can occur.
Have seen fbody headers choke 40+ whp off of a decent heads & cam LS1 before in a 99 T/A M6. The 98-99 manifolds are worse than the 00-02's but the 00-02's aren't all that. Anyway his car had a sweet little low lift 216/220 Comp Cam that behaved practically like stock and an excellent set of MORE Performance Stage 2 853 heads...dyno'd ~360 whp. Later car owner stepped up to a set of 1 3/4 inch headers and a returned and the cam made ~400+ whp, IIRC was 406 whp peak and kept its practically stock manners.
Excellent reason for a good tune as smell is as much a function of tuning as it is cats a lot of the time. I would waste time on an LS6 cam swap personally.
Bare minimum would be the well proven LPE GT2-3 cam 207/220 duration @ .050 lift -.571/.578 lift with 1.7 rocker 118.5 CL
Other choice with good manners that should work very well Summit's SUM-8715 Stage 1 Pro LS Ghost Cam. 222/233 115+3, .600/.575 Lift, Ultimate Stealth Cam
There are also lots of excellent choices inbetween these two to tailor for your ideal combination.
Might as well and do it once and do it right
Better valve job and cleaning up the bowl area will really help without having to do a full CNC. Of course appropriate vavles spring kit & new valve seals.
Unless you're endlessly stuck in traffic or sitting at stop lights or spending a half hour waiting in line for ☕️ coffee at Starbucks each morning, I'd get a quality set of long tube headers as the smell & hassle will be minimal. That's my experience driving with long tube headers & no cats since 1983.
Best of wishes with the project!
Hi, thanks for all that! I'll admit I haven't put much thought into the converter yet.
From what I understand the LS7 manifolds dump at the Kmember so they won't work sighhh. We don't have emissions testing here but I still need cats. I drive the car often. I also do get stuck in traffic and hit the drive thru more often than I'd like to admit lolol. I am very sensitive to exhaust fumes. For sure the tune will help tho!! The car is also extremely low. Long tubes wouldnt be ideal for my situation.
I will take a look at some of the cams you suggested.
Hey guys, finally started gathering more parts. Got the Holley oil pan, mount brackets and crossmember. Plan for the LQ4 is strip it down to shortblock and use the 853 heads I have for it. I got an LS2 cam for free off an 06 TBSS. What are your thoughts? I think it can be a good performer with the mild idle I need lol.
853s are one of the crappier LS heads, I myself wouldn't use them. 243s or 799s are a much better choice. They're generally available for $150-$200 used. You're building mild, so don't plan on that LS2 cam giving you much more than maybe 350 at the wheels. It simply doesn't have the capability of a well developed aftermarket cam. If you want a stock idle, get a cam with a really wide LSA that gives you similar overlap to a factory cam. Think of all the work you're doing. What's going to happen if you choose wrong on the cam? I know I would never do all that work to stab a stock cam in, especially knowing that even the mildest cams are going to be a 20-30 HP gain over stock style cams. The suggested Lingenfelter cam would be perfect. In regards to long tubes, my 2013 SS has LTs and high flow cats and I have zero exhaust smell, ever. And when I ran LTs in my Formula, I had no problems with scraping them. Remember, a lot of us have already "been there, done that" and aren't trying to steer you wrong, we want to steer you to being happy with your build. And to me, if you weren't interested in more power, you'd have asked how to build something as close to stock as possible. Give yourself a little more in the way of a budget, take a bit longer to build it, and be way happier in the long run.
243/799'S do flow more and have a little smaller combustion chamber which bumps the compression up so yes OP is leaving 15-20hp on the table here but with some work to the 853/241's they can perform just as well.
I have a CNC ported version of both an 853 and a 241. Ran them on my LS1 before it blew. They were ported using the same program, and seemed to work pretty well. Best time was 12.11@119. So I can agree, they have potential with work.
Going run the 853s for now. I really don't mind getting a better set of heads down the line. This swap is costing $$$$$$. I dont have a donor vehicle. Lots and lots of stuff to buy. Dont forget our CDN dollar is garage right now as well sighhh.
current combo is: LQ4 shortblock, 853s, LS6 cam and valvesprings, LS6 intake and Circle D 2800 converter Going with a Terminator Max for engine management. Next step is have my 4L60E core rebuilt.
243/799'S do flow more and have a little smaller combustion chamber which bumps the compression up so yes OP is leaving 15-20hp on the table here but with some work to the 853/241's they can perform just as well.
Lingenfelter has stated that the numbers on 243 heads can not be obtained with 241 heads. The as cast intake port on the 243 castings is superior to the 241 as cast ports, and if the 243 and 241 heads are both ported, the 243 heads are still superior. So, I disagree that the 853/241s can perform as well as 243s. If a good head man ports the 241s, they can be as good, or better than, unported 243s. But if both are worked, 243s are better flowing. Just sayin'.....
Small update -- Got a pair of 862s for really cheap. Will send them out to get cleaned up and have the valvesprings installed.
Ordered 12613412 injectors along with an LS6 valley cover and everything needed to swap it. Found a deal on a supposed good 4L60E with a shift kit, vette servo and .500 boost valve. Also came with a Vigilante 3600 converter but I'll run the Circle D 2800 I ordered.
Stripped the LQ4 down to a block and rotating assembly and ready to start assembling. Here is final part list (everything bought)
Melling high pressure oil pump
Holley pan
Rebuilt 862s
LS6 cam
Stock rockers with CHE trunnions
LS6 intake
Speed Engineering long tubes (yes I did it)
Hawks 4" catback with Holley Maximum Flow muffler
50 lb flexfuel injectors
4" Cold air
Terminator Max (backordered sighhhh)
Trick Flow balancer
ICT accessory brackets
Black valve covers with coil posts
Be careful with those speed engineering headers, a buddy of mine has cracked 2 sets. Looks like they dont know that stainless requires a back purge. Cool build btw
Street manners are amazing. It runs/feels/drives like stock. Got stuck in a 2 hour traffic jam, no problemo. Drives like stock. Put around 1500 miles on it so far so good.
No victims yet but had ZERO issues keeping up with a 22-23 Mustang GT on the highway.
Fume smell from being catless not as bad as I though, but I did buy a 4" cat and will run it as a tailpipe to see if it cuts the smell. That is literally the only place we have room to place it. It also has a bit of an ugly rasp if driving a bit aggressive at around 2300 so hoping the cat will eliminate that.
Currently building a nicer cold air and got some great Ebay hi tech parts lolol
- aluminum overflow (probably paint it black)
- aluminum rad cover
- aluminum dual fan shroud (let's see what fans are supplied, maybe upgrade them)
Will be adding A/C back in there, has to be top mount just deciding who's brackets and what compressor we will use.
Also shopping for tires. The General GMAX RS worked with my pavement pounding 305, can't really hook up now haha.
Last edited by GeorgeKlass; Dec 27, 2024 at 09:13 AM.
Reason: Dyno link wasn't working
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Newbie LSX build, need advice 
