07NBSChevy

iTrader: (1)

If you bored it to say 3.905" bore or whatever it is for a 5.7L and used Gen4 rods with flat tops pistons, have TSP port some 243 heads and mill them to achieve 11:1 compression while using the correct head gasket thickness to achieve 0.035-0.040" quench, use a TSP 228R .600/.600 cam or similar, longtube headers, LS6 intake with a 90mm throttle body with a good 91 octane tune.......you may hit 500 crank hp (around 400 rwhp with an automatic).

Or, you can built it for boost and blow past 500hp mark.

GLs1

Plus I'm kinda on a budget. So wouldn't it be cheaper to not bore it and keep the same pistons? And just upgrade as is with the same bore? Cause if I change the bore, then don't I have to change a lot like the heads and everything including the pistons? Just to achieve the same power?

07NBSChevy

iTrader: (1)

You don't need to change the heads on a sub 4" bore. I would use 243 heads with Gen4 4.8 rods and pistons if you want to keep it the same bore on a budget.

If you bored it to a 5.7, you will gain around 25-30 hp.

First off, what is your budget?
Second, what is your intended goal and use for this engine. Such as daily driver, drag car, and so on?

You wont hit the 500 crank hp with a N/A 5.3 without serious money, or boost. You are better off aiming for 400-450 crank hp with a 5.3 budget build.

The 5.3 build in my sig is right around 450 crank HP, so it kinda gives you an idea on what is needed. In your case, you can go with a larger cam and make a bit more power since your engine will not be in a 5,600lb truck.

WS6Store can get you a package on everything you need. Really good people to work with, with amazing customer service, as you can see they are on here 24/7 and literally get no sleep and strive to answer everyone's questions.

tech@WS6store

iTrader: (2)

You would not have to change heads if you bored rhe block. just pistons and rings.
Those stock heads wont promote 500hp though.
There is no need to go crazy with heads and cam like 07nbs is saying either though.
420 at the wheels in an auto is 500 at the crank. you can do that with a set of stock heads like a 243 or even 241 but youll need more compression such as using flat top pistons. A medium sized cam and a better intake manifold and you are there.
You dont have to spend alot.
The boosted way is easier but takes money also.

Boring a block is the same cost for .010 or .100 over for most machine shops. Our 5.3 pistons are same price as 5.7 pistons also. $220. rings are the same price also.

We have helped quite a few recently with budget builds. You dont need a slew of other parts to make a nice engine.

G Atsma

The 4.8 rods are too long, as the 4.8 uses a shorter stroke. 5.3 rods and 4.8 pistons would work, however

tech@WS6store

iTrader: (2)

You cannot use 4.8 pistons and rods on stock stroke. piston would punch through the head. He is fine with his stock rods.

G Atsma

I understand the 4.8 piston would work as the compression heights are the same, but the 4.8 is a flat top where the 5.3 is dished.
The rods are of course different with the 4.8 being too long to work in a 5.3.

GLs1

then it seems cheaper to bore it 5.7 and get new stuff, instead of force induction in order to make that power. Is that correct??

07NBSChevy

iTrader: (1)

I meant Gen4 rods with 4.8 flat tops.

In my opinion, if you want as much power as possible on a reasonable budget.

Keep the stock 5.3" bore, and use flat top pistons. Find a set of 243 heads and have them milled slightly for a bump in compression. Pick a cam, TSP 224r .600/.600 for example with BTR .660 Springs.

Or find a LS1 from a junkyard and start there.

tech@WS6store

iTrader: (2)

The iron 5.7l is the best option and will promote better power. not just in cubic inch but also compression ratio and bore size.
Our complete rebuild kit with 5.7l pistons, rings, new bearings, hi flo oil pump, hd timing set, thrust plate, and all HD gaskets and head bolts runs $620.
New ls7 lifters run $99
From there youd want to find a better set of heads. most go with a 243 you can find a set for $400-600 on here normally. id get them and have them cleaned and valve job. mill .010 off.
We have cam and springs for $515 and that would get you where you want to be as far as power range.

tech@WS6store

iTrader: (2)

The stock 5.3 gen3 rods are sufficient esp on a budget.

07NBSChevy

iTrader: (1)

I agree...they are, I personally use them in my builds. I find used Gen4 rods and pistons for $100 locally. It is not needed, but I prefer the compression bump from flat tops with the added durability of the floating pins in the rods, especially when using 243 heads on a Gen3, for a bump in power. That is for a 5.3 tho, if he goes to a 5.7, he can choose a flat top piston in the build.

I do agree on boring the block to a 5.7L wont cost to much. It will have more power and torque out of the box. Our shop has done it a few times and it runs around $200, which includes sonic testing the block, boring and honing all 8 cylinders and any deck surface machining for flatness. A good bore would be 3.903" or 3.905", I would not bore it to 3.908"

OP, what is your max budget on the engine build. It will help us determine your best options here.

GLs1

Okay then looks like I'll get it bored. And those kits from your store.
which should be everything to restore my engine? Anything else?
I'm trying to get this done before SEMA in November, and still have time to get noticed and into the show.

07NBSChevy

iTrader: (1)

WS6 Store, do you think he should worry about his Quench in this type of build, or just stick with a stock 3.910" 0.051" Head Gasket?

GLs1, do you have a cam picked out?

tech@WS6store

iTrader: (2)

Nbs no need in trying to overengineer the build. it will be just fine.

That kit is 100% complete for a fresh engine (adding the lifters also) It is the most complete and will get you everything you need.

We have quite a few cams but what really matters is
What is the engine going in to
What transmission
What intake manifold
And intended purpose for the vehicle like cruiser, weekend warrior, track car etc.

Answer those we can get you what you need as far as cam choice

GLs1

Going into: 2004 G35
Transmission: manual (not sure what model)
Intake: not sure yet, probably something not tall so it fits under the hood
Purpose: daily driver, yet occasionally taken to the track, body will be custom made for SEMA.
And eventually I will reengineer the engine, but for now the engine is on a budget but needs to be reliable with decent mid range power

G Atsma

Whose kit (if any) did you use to install it into the G35? Even with a 5.3 it will be a BEAST!

GLs1

I'm doing completely custom, getting clay to mold with. Then molding, and fiberglassing it myself. Will probably doing a front end tube chassis and possibly rear end too.

07NBSChevy

iTrader: (1)

I would bore the iron block to 3.903-5" with some flat top pistons. Use an LS6 intake and 90mm throttle body, and either get a cam spec'd or go for something around a TSP 224/228 .600/.600 on a 112 LSA. I prefer split duration cam.
Also pick up some 243 heads, have them decked .010" which will bring them to 63cc combustion chambers, BTR .660 dual springs, use a 3.910" bore 0.051" head gasket which should put you around 10.9:1 compression with 0cc flat tops or if you use flat tops with valve reliefs (such as -3cc), compression should be right around 10.5:1. Also, I would use a melling 10295 oil pump, LS2 cam chain and dampener, new sprockets, LS7 lifters, and a Pushrod measuring tool.

Compression was calculated using a Piston out of hole of -0.007".

WS6Store can hook you up with the kit with everything. I would also look into their new Needle bearing trunnion kit for stock rocker arms.

HP wise, should be at least 450 crank hp.

tech@WS6store

iTrader: (2)

An iron 5.7 should be higher than that crank hp wise. an ls6 makes 405 with less cam and cr. Our high lift hot cam makes roughly 450 off a 218/227. Using 853 heads. So 243s and a mid range cam would be worth the 475 range imo.