Building a 5.3 looking for horsepower

[todd7498]

I have already done a LS swap in my 72 last winter and love it, only issue I have is I want more power. I installed a 4.8 last winter because that is what I had with a 4L80E. I have purchased a 2007 5.3 now and want to build it for more power so I am looking for recommendations on building it to get as much power as I can for daily use. So if anyone has any recommendations on cam shaft, stall converter etc. please share what you think. Thanks

[BR3W CITY]

Daily use in old Canadia? Probably a procharger or a maggie. I guess it depends how high your looking to get (and how much you want to spend). You can bolt on a supercharger and still start the thing in January.

[todd7498]

I would love to do a supercharger but by the time I bought a Magnusson and tuned it I would be $10000 with our crappy dollar. So I am leaning towards less expensive mods.

[sweetk30]

always hear good basic cam / springs / headers and tune get you easy 125-150ish hp and still keep fuel mileage up near stock .

[nsb29]

Just about anything you did to it you’re going to have to have it tuned turbos are pretty inexpensive and can make big horse power even on a stock motor

[GIZZ]

Whats your budget? First I would get valvesprings and a camshaft, you'll want to do these anyways if you turbo it. I would wait on picking a converter until you know your final HP.

You could also try to find a cheap 6.0.

[mongocanfly]

This is a good read.....https://www.hotrod.com/articles/hrdp...g-bang-theory/....
Your 4.8 can build Some big hp numbers

[todd7498]

Thinking more along the lines of camshaft, valve springs and maybe porting heads? Intake and bigger injectors if there was anything to gain. Question is what is the best cam to go with? I would run a stall converter too.

[mongocanfly]

Unless you want a intake for show, a truck intake will flow very good....you can contact btr cams..and others...they will advise you ...i asked a similar question and got multiple answers...i called btr, told them what i had and what I wanted ..they hooked me up with a good cam and springs...no surprise ,when it came I had comp cams on the box...

[jrusher]

Im super happy with my ly6 build . Freshened up bottom end and heads are basically ls3 heads, Tsp stg 2 VVT cam, springs, ls3 intake and injectors, speed engineering 1 7/8'' headers. Engine rips good im probably into engine for 4-5 gs all said and done

[todd7498]

I am leaning towards a BTR stage 3 truck cam, springs, trunnion kit, port the heads, headers and a stall converter as of now. Obviously get it tuned. Not sure what kind of power to expect, hopefully 450ish at crank or more???????? I am running 3.73 gears and a 4L80E. Any other ideas? Thanks

[OutlawDrifter]

I like the BTR series of "drop-in" Truck Cams, keep in mind, the more you cam an engine, the lesser the street manners.

Since the beginning of time, most people have a tendency to overcam an engine to get the "lopey" sound, rather than the desired results of usable power. I don't think head porting will gain you good value in hp for $$'s. 2007 5.3 means you might already have 243/799 heads, should be good to go, if not, spend your money on a set of those instead of the port job.

What size of tire are you running with your 3.73 gears?

[72MARIO]

Originally Posted by OutlawDrifter

What size of tire are you running with your 3.73 gears?

For daily use i would be chosing a very mild cam and focus more on gear ratio and proper final.drive ratio for performance. The diffirence i feel between my 2 swap is amazing and it only because the faster one runs 250rpm higher on the hwy. My 6.0 with 3:73 and 32" tire is sluggish all around till 120 km
I would aim for 2200 plus at 100 km.

[todd7498]

I am running 29" tall rear tire.

[1971Stepside]

I have a 6.0 and went with the BTR Stage IV. They told me that would add about 75hp to the engine. I added the large tube headers. That is supposed to add another 20 -25hp. I'm hoping to hit 400hp once it is tuned. I don't think you will be close to 450hp with a stage 3 cam. Mine is together, but far from running at this point so I can't speak to the overall feel. Mine will only be a sunny day ice cream fetcher.

[OutlawDrifter]

Originally Posted by 1971Stepside

I have a 6.0 and went with the BTR Stage IV. They told me that would add about 75hp to the engine. I added the large tube headers. That is supposed to add another 20 -25hp. I'm hoping to hit 400hp once it is tuned. I don't think you will be close to 450hp with a stage 3 cam. Mine is together, but far from running at this point so I can't speak to the overall feel. Mine will only be a sunny day ice cream fetcher.

You two are talking different measurements, Flywheel vs Wheel HP.

Your BTR cam will add that horsepower with proper tune and headers, you won't see extra with the headers.

My LQ9 based 6.0 with the following mods puts 425hp to the ground:. LS6 intake, FMS F13 cam (230/232, .595/.585, 112+4), 1 3/4" primary tube mid length headers. Equates to over 500ho at the crank with a conservative 18% drivetrain loss. And it has a nice big flat torque curve.

That rwhp number is backed up with a scale ticket and ET at the dragstrip.

[71cadc10]

personal opinions:

cam around 216/224 .600 lift 112 LSA 108 ICL or even as tight as 110 LSA 106ICL
convertor 2800
headers if you like the look/ sound...they won't add a whole lot of power
portwork on the heads will help, mill .030 off. You don't need crazy CNC just basic head work by someone who knows the cathedral heads well. VJ + bowl work mostly.