4.8 vs 5.3

I just purchased a 99 Silverado Ext Cab (black) a few weeks ago. Didn't do much research on them as I really just needed something to get to work. Anyways, my truck has about 49k miles and has the 4.8 engine.

I feel pretty happy with the power of the 4.8. It is almost hard not to spin the tires leaving a light....but then in the mid to upper-range the truck kinda loses its' power curve. Just curious how much of a better performer the 5.3 would've been? My only mod so far is the MAC intake (which helped a good amount and makes a mean acceleration sound to boot!). I am still researching which exhaust to do, and still saving for a programmer. Thanks!

I own a 2000 5.3. I've only driven a 4.3 a couple of times, so I'm not sure if I can really help you. But what I do know is how mine runs, and it DOES run. All I've added so far is just an K&N filter, not the FIPK(later on). I can stomp the pedal at any speed and pass on the highway. Albeit, I can't race a porshe or something, I am very happy w/ my 5.3. I heard of guys on here that have done engine swaps relatively easily. Maybe it's a fuel problem? Hope this helps.

I have the 4.8L in my truck. I think it takes very well to mods. From racing many 5.3L and from driving my dads 5.3l, I would say the main difference in the motors in the amount of torque. The horsepower difference isn't very noticeable, but I can defenately tell the difference in the upper gears. Before the stall and shift kit, the only way I could beat a 5.3L was out of the hole. If I got the holeshot, I would barely win in the quarter, but if I spun too much, or hesitated, it would be over for me in the end. The 5.3L pulls so damn hard at the end of the race. Also, every year, the trucks get faster. For instance, right now a bone stock 2000-up will smoke a 99. I think it mainly has to do with the tuning from the factory. I have a friend with what I call a factory freak. It's an extended cab 2003 GMC. That thing has no mods, and runs a 15.2 consistantly. He would always pull me in the end, until I got a few more mods. :evillol: Now, he sees taillights.

Well,

Sounds like with a few more mods I should be able to run with a stock 5.3. I can't wait to take the truck to the track.....I'll take anything there. I took my 2000 Caddy DTS which everyone snickered at...until I beat a Stang that couldn't hook up, with my 15.0 run. The video is funny...you see the Caddy fly off the line, then you hear major 5.0 panic with him spinning tires all the way. :grinno:

i have a 2001 4.8L silverado itll run with ne of 'em...heads and cam, straight pipe connected to gibson headers o2 simulators(for state inspection with straight pipe) 4.10 gear ratio, hypertech, k&n fipk2 kit, flex a lite fans,maf sensonr, mid 13's all day without slicks IMPORT KILLER bored it stroked it SMOKED IT

I dont know about the 99 versions of the 4.8 and 5.3 other then their numbers (255 hp/270 hp) but the 2000 4.8 and 5.3 will scoot! My friend's papaw had a base Silverado extended cab 4x4, no chrome, jsut plain jane with teh 4.8 and it would absolutly fly! You could be going 25 mph or so and stomp it down andit would literally throw you back in the seat and then ALMOST tach out at 6000 rpms before it would shit!. It would fly. The 5.3s are nice to. Rolling at about 45 mph, it takes very little time to get them to shut down! My papaw has an 04 Z-71 extended cab with the 5.3 (295 hp for 04) and I can tell it has more horses then his old 2000 5.3. This truck will really get away with you. I mean if you don't set cruise, then you will be doing 75 and 80 mph before you know it, and it will eat a hill up!

If I were you, I would get some Flowmasters and the HyperTech Programmer and 160 degree thermostat and be done with it!

The stock 4.8L is no slouch, but there is a big difference between the stock 4.8L and the stock 5.3L.

You would definately notice the difference if you would compare them on a pull.

-slacker

I've got the 99 5.3 and it's damn strong, but I've been told with a custom tune, I can get at least 50 more horses out of it. They say the factory tuned the 99's weaker for some reason, I dunno how trus this is, but a custom tune is in the very near future for me. All I need is someone to buy my Hypertech.

I'm very happy with the performance of my 5.3. My firend's father in law has a 2000 4.8 and always talked about it being quick.... he got in my truck and nearly shat himself when I hit the gas.

Sounds like you boys need a ride in my 6.0l! :naughty:

LOL! If I had the 6.0 he might have had the big one right there! I don't know CPR!

I want my Nelson's tune ... :crying: