L7 Sierra

Does anyone know the cam specs, and Valve spring specs for the 07-08 GMC Sierra 4.8 liter V8?

Also what is the biggest ratio rocker I can add? I see 1.85's in Comp Cams catalog, and would love to add them to my motor.

I do not want to do a cam swap, since I plan to do a engine build in 2 years. And only want to add products that transfer between motors easily, and cam selection between a 4.8 vs 6.2 can be quite different.

viciousknid

iTrader: (8)

Not sure on the stock cam and springs specs But most likely under .500 lift And Rockers are only going to make things look pretty when you pull the covers off.
2 years is a long time considering a cam and springs swap can be done in about 7 hours depending on your tools.

L7 Sierra

I just want a few more ponies, while I fix up other things on the truck that suck up money. Also some of them are being done in preperation for the bigger motor.

Such as my 10-bolt is a 3.23 peg, and it needs performance upgrades to last.

The 4L60 is not bad for driving, but usually doesn't last when you get on it. And the 4L80 or the new 6L80 won't be free.

Also I want to put in a airbag suspension with a 3 link for handeling.

So I just need something to tide me over.

Ross @ EDO

iTrader: (5)

cam/spring setups are cheap provided that you do the labor. IMO, I would do all of the bolt-ons + a tune, then start worrying about cams and such

InchUp

iTrader: (2)

So you'd rather spend $500 on 1.85 Comp rockers that are only going to make piston to valve clearances a bitch to figure out (since they aren't gonna make any more power) instead of a simple $100 dollar LS6 camshaft and matching $53 dollar springs?

Stock cam is a 190/191, 0.466" / 0.457" on a 114 LSA. Springs are good for just under .499 lift from the factory.

viciousknid

iTrader: (8)

That was my point too. Rockers will only make it look pretty with the covers off and that's it. If you just want a lil extra power to start with consider a used cam is $100-$250 depending on the size. springs anywhere form $57 shipped to $120 depending on brand. install is about 7 hours if you do 1 spring at a time and have the proper tools.
Tune will net you a big improvement $300-$500
LT,s and full exhuast would bring in 15-30 if you tune it right.
And the 60e will hold up to any of those mods for a long time.

Not saying you should do this over that, but if your seriously considering changing rockers to get that 1 or 2 hp you may or may not get. Why not take that money and put it toward something that's actually going to help you?

And unless theres something different on the 6.2 that i'm not sure of compared to the 4.8 then everything can swap over. The only thing i'd question is the cam because I don't know if the 6.2 has a different cam position sensor location or not.

Again. Just making sure you're aware of all your options before you spend money on Rockers. I know a guy that actually threw a brand new set of compcam 1.8 rockers in the trash because they weren't worth having.

BTW Inch, where did you find those specs. i've been wondering the factory specs but can't ever find em anywhere.

L7 Sierra

Rockers one the old sbc were always an easy upgrade for up to 25 hp.
1.5 stamped to 1.5 roller up to 15
1.5 stamped to 1.6 roller up to 25 "and usually as such"

So I was wondering if the Gen 3 0r 4 SBC were the same.
1.7 stamped to 1.85 roller should be up to 25 hp. Especially since alot of you guys say it responds so well to the LS-6 cam which pretty much does the same thing, but with stamped rockers.

Sam88Gta1

iTrader: (13)

These motors do not have stamped rockers.Stay away from the aftermarket rockers.The comp rockers will not fit the 6.2.

InchUp

iTrader: (2)

Stamped on a 21st century motor? Not a chance.