270HP VS. 285HP

[rocksolid]

Does anybody know what GM did to the 5.3L, to get more hp's out of the two?

[Frank S]

I'm pretty sure that they started using the cam from the 6 liter but I've also heard that there was some computer tweaking.

[Roofer]

I heard the cam thing too. Also the '99 5.3's rev limiter is at  5200RPM, and the '00 is at 5600RPM.

[Zane]

All it is is the cam from the 6.0L. I do not belive anything else was added.

[stumpy]

I know this is a thread revival from hell, but im bored and decided to look around on your site. The thing they did was a different cam, I don't know if it is from a 6 liter, and something they modified to the starter. I have no idea why the starter would help out. But thats what they listed different on the engine to make more power.

[redvett]

If i remember right it was cam,heads (aluminum) & calibrations.

[stumpy]

heads (aluminum)

 

No, they were already aluminum in 99 also. The calibration would have to be with the different cam.

[redvett]

When the 99's were going down the line they had iron heads and my 00 & 01 had iron on them but they were 5.3L not all had aluminum the first couple of years. I think exhaust systems were different too.

[RaysZ71]

When the 99's were going down the line  they had iron heads and my 00 & 01 had iron on them but they were 5.3L not all had aluminum the first couple of years. I  think exhaust systems were different too.

 

<{POST_SNAPBACK}>

 

 

 

 

The only LS series engines that had Iron heads were the '99-00 6.0L. The 5.3L had aluminum from the start. My truck was built in 10/98 with aluminum heads.

 

I heard it was cam and computer tweaks.

 

has someone actually dynoed the two to see if there was actually a difference or did GM underrate the '99?

[DanW]

When the 99's were going down the line  they had iron heads and my 00 & 01 had iron on them but they were 5.3L not all had aluminum the first couple of years. I  think exhaust systems were different too.

 

<{POST_SNAPBACK}>

 

 

 

 

The only LS series engines that had Iron heads were the '99-00 6.0L. The 5.3L had aluminum from the start. My truck was built in 10/98 with aluminum heads.

 

I heard it was cam and computer tweaks.

 

has someone actually dynoed the two to see if there was actually a difference or did GM underrate the '99?

 

<{POST_SNAPBACK}>

 

 

 

 

My 99 Silverado was built in September of 98 and it also has aluminum heads. Funny thing, though. That 270hp 5.3 felt every bit as strong as my 03 Tahoe 285hp and my wife's 295 hp Suburban (04). Of course, it had many more miles on it. That was one mean motor! I miss it.

[michigan2500hd]

My 2000 5.3 feels every bit as strong as my 05 5.3 does. It actually feels like it rev's quicker but that could be because the 00 has a cable operated throttle. Man will the 2000 kick down and move. I cant feel a 25 horse differance between the two.