So I currently have a 6.0/prc 2.5 5.3/ fast 102 setup with a Comp lsr cam.
The 6.0 is on its way to needing reringed, and obviously his is not a super boost friendly setup.
At this point, I'm strongly considering picking up a 5.3, gutting the goodies from the 6.0, and swapping everything over.
I want to run the same h/c/I combo on the 5.3 n/a as I collect up the turbo parts and an FI cam.

So here's where all the questions come.

My heads were worked further at tsp before they shipped them, and I am not sure what was done. BIG problem in my book.
So here's where all the questions come in.
What's the best year 5.3 to grab up? What kind of compression will I be looking at?
I want to shoot for 600-700hp on a low boost streetable tune, with the room to grow up to the 800-1000 neighborhood on a high boost setup.
What can a stock 5.3 handle?
This is my first turbo build outside of the dsm world so any pointers are appreciated!

 

Might consider a 4.8. It's the strongest LS motor for boost

 

I'm curious, what are your current cam apecs?

 

Your 6.0 can handle all of that power you're looking for easily. The only problem is knowing what the compression ratio is, because with those heads and flat top pistons (if that's what you have), I would really be worried about boosting it.

Until you can get some dished pistons for boost, I would probably throw some 317 heads on it to lower your compression. If you have a good tuner then you could get away with a little higher compression. I'd talk to tsp and see what it is, but I agree with you, the heads would be my main concern for that reason, and the next one would be the fast intake. From what I understand, they aren't very boost friendly, so you may want to throw your ls6 intake back on if you have one.

I'm still learning about boost myself and don't know a lot yet. But I believe a stock bottom end 6.0 is good for between 600-650rwhp on pump gas with a good tuner. I believe Denmah is pushing over 800rwhp with a stock bottom end 6.0 little John stage 2 turbo cam, and a s480 knock off, and either meth or e85. So once you forge your 6.0 for boost and have the right heads combo, I think you'll have no problem making over 1000rwhp.

A good tuner is everything and I think if your compression isn't too high, that you can get the 600rwhp out of what you have until you get your parts together.

 

N/A heads and cam don't usually work too well with boost.

You could sell the heads/cam/intake and 6.0 and break even on a turbo 5.3 build.

 

Hmm i seem to have done well on my non boost friendly lq4 with 228r/112lsa cam and milled 243 heads made 610whp and 630tq with 12psi on 94 pump gas but my tuner did spend over 2 hrs dialing it in bit by bit to be safe.

My new setup Im looking to make closer to 700whp with some more boost and a splash of meth.Tune will make or break a motor that is on the higher side of compression and jamming boost..you cant get too greedy like I have or parts go flying.

 

I can see a lq4 on 94 octane and a good tuner living on that. That is a smaller sized cam for a 6.0 and I imagine works pretty good. Tuning is everything

 

Lol it did for a solid year of abuse...untill I got greedy and pumped 18psi on it. Cps o-ring and rear main lost the ability to seal oil and sure enough my angry boosted lq4 made its last 5 pulls spinning 4th gear and my lifters gave out and parts began to fly and the car began to slow down Live and learn.

Now that Ive tasted 18psi ..I cant go back to 12. My new lq4 with see ljms stg 2 cam,317 heads milled .030,btr dual springs,ls7 lifters and bushing upgraded rockers.650whp is the minimum goal on pump gas.

 

Yeah that's going to be a fun car and you'll easily get 650rwhp out of it. With meth I'd push for close to 750rwhp lol. I know what you mean about after feeling that much boost, not wanting to go back, because my buddies car was alot faster than mine and I felt slow.

Your mishap is why I pulled my ls1 out. It only had 22k miles on it and sbe pushing 529rwhp/529rwtq on 9psi, 11 deg timing with stock 241 heads and btr stage 1 turbo cam. I was afraid it was going to let loose on me and I didn't want to tear it up.

 

The cam is the 285lr- 235/242 .621/.624 113lsa

I really wanna stick with these heads and that's why I wanted to go the 5.3 route. And unfortunately I do not have an ls6 intake around, so the fast intake will be staying also.
Consider this the ultimate budget turbo 5.3 build. Everything else is my tuners problem lol
On a side note, I had never even considered a 4.8
I was hoping to grab a cheap good running 5.3, give it ARP rod bolts, throw my h/c/I at it, and drive it n/a like that while I collect up the turbo goodies. I only plan to run my big cam till it's turbo'd.

 

And not that I have the $$$ layin around, but I've been starring at this thing for a while..

http://www.ebay.com/itm/282070082163?redirect=mobile

 

Ultimate budget turbo 5.3 build?

'budget' and fully forged shortblock with FAST intake and PRC heads don't go anywhere close to the same sentence together.

 

Well the heads and intake have been on the car like 4 years, so I'm not including those $$$s in the "budget" lol

After speaking with a few engine builders in the area, it's sounding like the best/cheapest route is to stick with the 6.0 at higher compression lower boost.

 

I don't see how that's the best route either. A higher compression/lower boost setup will always make less power than the same engine with less compression and more boost.

 

I'm seeing a lot of 4.8's for 200-400 bucks around me and it's getting really tempting...

Anybody have any opinions on the idea of a stock 4.8(ARP rod bolts and head studs), the prc 2.5's, a tick stage 2 or 3 turbo cam, on3 78mm turbo, and e85?
I spoke to my tuner and he basically said if I'm on e85 he can make just about anything work lol
I have no problem spending 300 bucks on a 4.8, boosting till it pops, buying another 4.8, boosting till it pops, and so on

 

You have to figure in the cost of heads if you do a 4.8. The heads on your 6.0 probably(definitely) have valves too large for a 4.8 bore. Other than that, I wouldn't even spend for rod bolts on a 4.8. The connecting rods are just as likely to bend as spinning a bearing from bolt stretch. The good news is that either one is unlikely below the 1000hp range give or take 100hp. Almost forgot, open the top ring gap for big boost so your ringlands don't break when the gaps butt together and bind. Lots of people are using junkyard 4.8 motors as disposable bottom ends in race builds. I'm not sure how many are actually disposing of them.

 

Would the bigger valves wouldn't be a problem with a 5.3? I didn't even think about the different valve size of the prc's. I know 4.8's and 5.3's have the same casting heads, but with the amount of different heads ive seen on 5.3's I'm assuming the bore is big enough that it doesn't matter.

 

5.3's have the same bore as the 4.8, but with a longer stroke. The only advantage the 5.3 motors have is an inexplicable increase in fuel economy over the 4.8 in bone stock factory trim.

 

Well, more possibilities have opened up.
A buddy just offered me his stock lq9 heads, and enough cash for valve Springs to do his h/c swap for him. I really dont wanna re-ring the 6.0, which has me still thinking about goin 5.3