Silverado Engine ?

**kool-aide** · 12-02-2007, 05:57 PM

I don't know squat about GM Trucks, and my brother is not very knowledgable either.

He has a 99 Silverado Reg Cab with I think the 4.8L V8. I'm guessing cuz I finally got him to email his performance build sheet and it said COMPLETE REMAN 4.8L ENGINE BORED .20 OVER.

So what was the stock V8 on a 99 Silverado? If it was the 4.8L what would the stock HP and Tq be?

Would it be the L460E Transmission with 3:23s? I know they dropped new 3:73s in it and a 2400 stall. But have no clue what they started with.

This wasn't the biggest badest truck whne he bought in 99. It would have been your run of the mill i can't afford much. And asking him to read RPO codes would be like a root canal.

What kind of block is this? Just lookin for a point in the right direction and some of the typical basics on what he has. Every time I ask him he is like, dunno. He really doesn't know what he has or what it is, he just drives it and pays some one else to work on it.

His dyno sheet shows a peak of like 238 Tq and 227 HP at the wheels, obviously not stock.

Thanks

kool-aide

**Tyler_LS1** · 12-02-2007, 06:02 PM

The 4.8L put out 255HP and 285TQ stock and the Tranny is a 4L60E.

Those number seem way low

**kool-aide** · 12-02-2007, 06:40 PM

255 crank or wheels? What i've heard is the avg LS1 will dyno upper 280s to low 300s but every one knows GM rated the engine at the crank not wheels. So 227 is only disturbing based on the enige work done, unless they screwed up on the build and can't run a dyno.

I thought 227 was low too considering the work. Remember I'm getting third hand info from a not too expert of a source. I saw the dyno sheet so that is spot on. Heck I'm still trying to figure out how his truck weighs 4500 lbs. That seems high. 4200 lbs tops IMO.

Now I once had a Dakota R/T, the 360 not the smaller engine they used later on. It was rated at 250 at the crank. I never verified it, but the only work i did was cat back and I could run upper 14s and some times mid 14s. Now i did have 3.91s in it and paid at the pump to match.

That's why I was curious about the numbers and what he had stock. Now his engine had 140k miles on it prior to work.

Do you know if this is a sleeved block? I'm guessing no, based on a guess it is an iron block. I have no idea.

Any way, thanks for the help, and I hope to carry this conv on further.

**Benner** · 12-02-2007, 06:58 PM

There an iron block LS-series engine aluminum heads. The 4.8L was the little brother to the 5.3L whick he can easily make out of the 4.8L. I'd say those numbers are probally correct considering The stock numbers are at the crank and he doesn't have anything besides the .020 bored over added. Id say with a tune he could probally add another 15 hp and 15 to 20 ft/lbs to those numbers.

**kool-aide** · 12-02-2007, 07:07 PM

well as far as i can tell he has some kind of LS1 CAM. It didn't say what it was other than LS1 CAM. He has JBA shorties. I know he has dual exhaust but would assume cat back considering he still has the cats and lives in Texas.

So I would list his mods as

CAM, probably mild
JBA headers, ceramic
1.75 roller rockers
cat back dual exhaust, don't know what kind
twin scoop ram air hood, functional
dyno tune

he said before the tune it was making about 196 at the wheels. This is his second tune and went from 196 to 227. The only work done between the two pulls was the 2400 stall.

would he have the same LS heads that an f-body would have?
what kind of TB does he have, twin or single bore? I asked and he couldn't remember. I am guess the twin bore style.

He's supposed to be getting a ported TB in the future. And I hear saving for push rods cuz he's still running stockers.

**Benner** · 12-02-2007, 07:29 PM

Okay now that you tell us those mods I'm going to say it's probally a little low on power. No it's not the same heads as the LS1's. Somewhat similar but not quite the same. The 5.3L heads are very sought after heads for installing on LS1's once ported and polished.

**kool-aide** · 12-03-2007, 05:01 PM

ah. my brother is going to start posting his specs on cardomain. if you want to see what 23k grand buys you search for CavSct. He told me today its a Comp CAM. Like I said I hope to get him posting more stuff cuz he really loves his truck.

http://www.cardomain.com/id/CavSct

is there a good place or link with lots of info on this 4.8 engine?