1970-Cloned

iTrader: (1)

I have a stock LS2 out of a 2006 GTO 24 reluctor wheel engine.

The engine was a pull from a wrecked car with 5000 miles.

I put a comp cams 265HR, very small cam that makes great low end and mid
range torque.

After getting the engine running it make a noise. I have posted a video of the problem and no one knows what it could be. It is in the engine as we took off ever external part to make sure before we pulled the engine.

Instead of having the machine shop touch the 243 heads, I am thinking of buying some LS3 take off heads and LS3 intake.

Would this be worth it with the cam I am using? I don't want to go to a larger cam because this will be a driver car.

Will my stock LS2 throttle body work with the LS3 intake?

Let me know your thoughts or opinion on what direction I should take.

Thank you for your time.

low2001gmc

iTrader: (148)

sounds like your performance build is mild by most standards and in that case i dont see the point in spending money on a head and intake swap. just have mechanic or machine shop go through heads to ensure everything okay, slap back on and enjoy.

if you were going with a bigger cam and more for performance, then i would go with the ls3 head and intake swap.

RoidedSS

for the ls3 heads and intake, you won't get everything you can out of that setup without choosing a different cam. typically from setups I've seen there is a large split in duration for that top end. I'm sure more people will chime in, but send the 243's to AI and have them worked over. A lot of people have gotten great results out of those heads.

1970-Cloned

iTrader: (1)

What size of cam would you recommend to use with the LS3 heads/intake.

The only reason I am looking at these parts is that I would rather buy brand new take offs or pulls than have a machine shop do work to the LS2 heads. Not saying they can't do a good job. I would rather buy new parts than have machine work done if I can avoid it.

It is hard to find stock LS2 heads that aren't messed with.

Thanks for your time.

MX6.0

The LS2 throttle body will bolt right up to the LS3 intake. The MAP sensor is different on the LS3's so you'll either have to adapt the old MAP sensor or get a new one (easy job and well documented).

Ive run a stock LS3 top end on a stock LS2 bottom end for about 5K miles and love it. The cam is a EPS 222/230 .591/.608 114+4 and it puts down 430rwhp / 410tq with shitty shorty headers, cats, resonators and a muffler.

Tainted

iTrader: (9)

I wouldnt put on ls3 heads.

Everyone likes brag about how good they flow but heres some things you should know before you do it.

PTV clearance, that big *** intake valve is not made for a 4.0 bore. the valve will be right up agaisnt the cylinder wall, its going to hurt your flow, ability to mill for compression, and limit your PTV clearance for larger cams.

Having said that, you are better off staying with a cathedral head setup. Im sure a dozen people are gonna say ohh youre wrong blah blah blah.

Do your homework, read psots by predator z, pat g, tony mamo etc. they will all tell you square port is NOT the way to go on a 4.0 bore

Zfan

Wrong cam for LS3 heads and intake, you need a wider split duration. Why not just clean up/port your 243 heads. Probably cheaper than doing the LS3 mods.