spencer_clark30

So I've decided to upgrade my LQ4 a bit, but need some advice. I've decided on a 224r cam from TSP, along with a few other odds and ends in between, but I'm not sure about the heads. I was originally just going to get the spring package that they came with, but I really like the specs of the factory L92 Heads. Is this the best choice for me? I've heard many say that LS3 heads tend to be better for just an overall power setup, without sacrificing low end power. I plan on a torque converter and shift kit soon after this setup too. I'm not exactly sure about which Head gasket to go with either. The motor is a 4.00" bore I know, but how big of a gasket do I want 4.02? I have all the tuning capabilities I need so I want this motor to have it's full potential and the biggest bang for the buck, without having to spend a small fortune. Also with the L92 Heads would I need a different intake manifold? I currently have the stock truck manifold. Thanks.

madmann26

iTrader: (7)

L92 heads are square port. You will need a different intake manifold.

You could do a LS3 top end conversion but you would need the related harness adapters.

You would need an xlink to use the LS3 throttle body with your Gen3 pcm.

The TSP 224 cam won't work well with the LS3 heads. Sure, it WILL work but it's definitely not optimal since the LS3 heads want a lot more exhaust bias.

IMO, stick with the cathedral port setup and do a NNBS intake conversion (have to get an xlink adapter).

spencer_clark30

So would you just get the Cam spring package, and call it a day? As far as the manifold I'd really rather not switch as I've done a lot of research on the different ls manifolds, and the truck manifolds perform just as good as any other ls. Are there popular sets of heads that work well withe the 224r?

Atomic

iTrader: (42)

They make a rectangular port truck manifold (the L92).

You would come out better if you just have the heads milled a bit to bump up compression and have them cleaned up.

madmann26

iTrader: (7)

They make a NNBS intake manifold that is cathedral port and flows better over the NBS intake and is more or less a direct swap. For heads, 799/243's are about as good as you can get for NA unless you go the 317 route and mill them down some.

spencer_clark30

I was actually just looking at this and I believe I've narrowed down my decision to either 241 or 243 heads. I feel like the 243's are better overall, but you can get 241's for hardly anything anymore. I really would like to increase the compression rate with one of these sets, as I've read the 224rs run well with bumped up compression. But then once again I have the head gasket problem. I'm truly clueless as far as that, as I mentioned in the first post. I saw one guy recommended one with a 4.02 bore and a .051 thickness, and said it would help compression.

Atomic

iTrader: (42)

The 317s and 243s are identical except for the chamber volume which milling the 317s can mostly make up for. Stock MLS gaskets will be fine. If you plan to run a power adder might go with the LS9 headgaskets.

spencer_clark30

Oh ya that's good stuff. You guys are saving me $$$ by the minute Now where can I go about getting them milled? Can most any machine shop do it or, would I have to send them in, and also by how much would I want them milled if it were you?

Atomic

iTrader: (42)

Yea any decent machine shop or engine place should be able to do it. Around 30 thou is pretty normal. Stock chamber volume is 72cc and 243s are 64ccs, and 1cc=6thou about. So you basically go from 72 to 67. Mill too much and you risk piston to valve clearance problems depending on your cam.

madmann26

iTrader: (7)

In addition to milling them too much, you run the risk of the intake not sealing correctly due to being misaligned if you have too much taken off.

Like Atomic said, around .030 is pretty normal and would be a nice bump in compression.