I want to get a 4.8, add ARP hardware, LS9 head gaskets, LS6 cam, springs, and intake. Also in the plan is a 76 mm ebay turbo and making my own kit running 10-12 lbs.

Does anyone know off hand what heads come on the 07+ LY2's? Are there any options down the road for more power heads wise?

I know the LS6 cam will go in a 5.3 all day long with no problems, is this true with the 4.8?

I am absolutely clueless about injectors, HELP!

What approximate power range should be attainable with this combo? I would think the bottom should be safe to about 600 RWHP as a 5.3/6.0 would, correct?

 

Anyone?

 

Since a 4.8 is a truck motor cruise over to performancetrucks.net and look at foose04.

 

-Get arp rod bolts, skip the ls9 gaskets and use stock mls,ls6 cam is good,and what intake? 4.8/5.3 heads are the same and the ls6 cam will go into any gen3 motor

-If you want to lower the compression some put some low cost 241 heads on there

-For 600rwhp you will need a minumum of 60lb injectors with a return fuel system with the appropriate pump...you could easily reach your goal with 15psi

check out performanrtrucks.net for more 4.8/5.3 info......

 

Ah ha I won!!

 

My objective for this build is a baby step... I will eventually swap the 4.8 for a 6.0 aimed at the 900+ hp mark. I want to get some extra power, but not so much that I destroy a poor little motor for nothing. I need the motor to last a while, so I figured that 10 psi and a good tune should hold me over.

I have seen the ls6 intake used on the 5.3 for boost, I figured it would be a safe bet.

If I get some 60lb injectors and run closer to 500hp rather than 600hp, I should be gravy, right? My uneducated guess is somewhere around the 500rwhp mark on 10 psi. Can anyone confirm this?

 

why skip the ls9 gaskets?
ls9 gaskets are close to same price as reg mls but designed for boost i see no reason not to use them

 

My truck is an 07 new body style, and it has the 243 heads on it. Which should be good for your setup, just have them ported. Injector wise I have some 71#s for sale which took my car to 650rwhp without any problems.

 

the newer 5.3/4.8s come with 243 heads

 

honestly for only 10 psi i would not even bother changing your heads unless there already off because most 4.8 motors are 9-1 comp ratio from factory.
As far as injectors if your planing on a 900 + hp build later i would buy injectors that you would use for that build (like 100 #) there is no sense in buying injectors twice and with a good turner they should work fine for this build
also you should be 500rwhp range at 10psi but there is a number of factors
main ones being your tune, your parts selection, and drivetrain

 

Well, I do not even have a motor yet, I was hoping to pick up a 4.8 with my tax refund. I know where one is for $350. I have a 94 Firebird Formula, but I am not sure if that will be the project car or not.

I am going to get the motor the way I want it before I decide what to put it in. I was thinking of building the 4.8 later on, but the 6.0 has more potential, so the 4.8 will not get a set of heads. Just cam, springs, head gaskets, and intake for now. I will then swap parts to make it fit in what I decide. After that comes boost.

 

the 4.8 are strong motors, ive seen / heard of stock bottom end 4.8 making 800+ hp
for how long idk lol
as for mine im looking to make at least 700rwhp with e85 at probably 18- 20 psi and that is a stock bottom end 4.8 with arp bolts and ls9 headgaskets and 317 heads

 

From what I have heard and seen, 600rwhp is about the "safe" limit on the bottom end with a good tune. That is where I came up with my goal of just over 500 rwhp.

 

So is everyone pretty much in agreement that I may have a decent combo lined up here? 4.8, LS6 cam, LS6 intake, LS6 valve springs, LS9 head gaskets, and 60+lb injectors for about 500-550 rwhp? It will be a LONG time before I get to the big time build, so I just need the right injectors for now.

 

So I heard that the LS6 cam has a smaller base circle (.050) than an LS1 cam. Does this apply to the cam in the 4.8? Will I need longer push rods?

 

that honestly wouldnt make ANY sense. where did you hear that?

 

http://sdparts.com/details/gm-factor...parts/12565308

Right there in the print. Apparently the LS6 has a longer valve stem? Doesn't make sense to me, but I have a lot to learn too.

 

well god damn. i have zero experience with the cam, i couldnt tell you. but i've never heard of anyone running into problems. in any case, check wipe pattern before you run it.

 

I suppose I will check on some numbers with a company that would have the proper information... I know Scoggin Dickey is a well known company.

 

Change of plans: found a 5.3 for $275 with an LS1 intake. Same bore as a 4.8 at 3.780 right? I hope to still use LS9 head gaskets.