Well, this is just another swap but I wanted a place where I could ask questions or maybe this could help somebody else in the future. I rebuilt the 305 TBI in this car about 12 years ago now its time to go bigger. At this point of making this thread the motor is almost done but I will start from the beginning.

So, I started with a 2002 LQ4 (6.0L) for $1200 w/ computer and harness, which I don't need but I will cover this later. I bought this last year and found out it was already a rebuilt some time ago. But none the less sent it to the shop and found out it was already bored .020 over. The shop was able to add another .010 because I wanted to make a stroker motor out of this.

Cost (Updated: 03-22-2020):
$1200 - 2002 LQ4 (6.0L) w/computer and harness
$1635.95 - 408 Stroker Kit (CNC-6103-SRP) 58x Reluctor wheel
$92 - LS9 Head Gaskets (BTR-22033)
$433.00 - Comp Camshaft (54-459-11)
$484.99 - Valve Spring Kit (26926TS-Kit)
$80 - Cam Bearing Tool (SUM-900131)
$136.96 - VVT Delete Combo Kit (09-0027) from summit 4x timing gear
$1350 - Holley Terminator X Max (EV1, 58x, 4x) w/ canbus connector
$126 - Pump Kit (SUM-PumpKit1)
$20 - Exhaust manifold gaskets (BTR17944)
$81 - F Body Oil Pan
$50 - F Pan pickup tube
$65 - Head bolts (SUM-127001)
$110 - Walbro 255 Kit (GCA758-2)
$180 - Radiator (166-EC951)

Total: $6044

 

Engine before going to shop, sorry for the image quality old phone at the time.

 

Glad you started a build thread. Welcome to the LSx forum!

 

Welcome. What are your plans for the heads and what compression ratio are you shooting for? What bottom end kit is that?

 

Right now it has 317 heads I will eventually replace maybe 243's. I think the ratio is right around 10.8:1 with the 317 heads (71cc), I wanted to be around 11:1 and I don't have e85 readily available in my area. So if my area gets more e85 pumps I would probably swap the heads and run e85. The lower end contains: Scat 4340 Forged I-Beam Rods, Eagle Forged Crank(534740006100), and SRP Forged pistons (329378).

 

I would hate to see that combo suffer from 243 heads. At the minimum I would look at TEA's or advanced Induction ported 243 package if you don't have the coin for aftermarket heads.

 

I would love to get my hands on some decent heads but at the moment just not in the budget. Just to humor me what heads would be considered medium and high end?

 

When it comes to heads there are a few ways to go. If you are budget minded I would sell the cathedral port heads (317 and 243) and buy a set of LS3/L92 rectangular port heads and an LS3 intake. Those heads in stock trim will feed that 408 better than untouched 243's. You can port the 243's, and make great power, but it will cost you more than getting a set of LS3 heads with matching springs (for the cam you have). Also, the LS3 intake is better than any OEM cathedral port intake manifold and will allow you to run a larger throttle body (90mm min). If you go aftermarket your choices are endless depending if you want to go cathedral port or rectangular port. Companies like Mamo Motorsports, AFR, MAST, PRC, and Trickflow all make great heads in multiple configurations and can spend time talking with you to get you the right set of heads for your combo.

Your swap is going to need a million other things besides just the engine. You will need to upgrade the chassis, fuel system, exhaust, brakes, etc etc. Those cost money so if its not in the cards I would look into the rectangular port heads now. It will cost a bit more than running your 317's as is, but will give you way more power. You could also sell the old parts to recoup a bit.

 

What if I said it this way, I don't have intentions of racing the car just a fun project and have a smile when I do drive it. Can an ls3 intake with stock injectors handle this because I still have not decided on an intake yet? I did upgrade the rear end to a 4th gen not saying it will handle it but its a start, Walbro 255 and 3-inch exhaust already. I have no problem trying to sell stuff, I have an ECU, harness, 317 heads, old truck intake w/injectors, hooker headers 2055 with y-pipe, and more laying around that I can sell. Thanks for the feedback Shiftycapone.

 

Yep, just like most of us here (including me). Very few real racers.

This thread was started recently and has a whole bunch of 10 second engine combos. Seems the 408 builds often have cathedral heads.

https://ls1tech.com/forums/generatio...or-builds.html

 

4th gen rear gets you a posi and disc brakes but unfortunately that's it. You'll likely need injectors regardless of what intake you choose. However, you often can get an Ls3 intake with rails and injectors for under 400. An ebay 90mm throttle body and the cost of your heads and you are all set. You might actually spend less that way than buying an intake and prepping 243 heads.