Well, I'm putting an LQ4 in the wife's Tahoe. The Ho is a 2002 2wd ex-police vehicle. It was originally a 5.3L flex fuel. I'm deciding between just sticking the LQ4 in there or putting it in there with the 5.3L heads. Here are some of my options:

Put the LQ4 in there right away, dyno it, and run it. Later install cam and heads.

Put the LQ4 in there with the 5.3L heads as is and dyno it, and run it. Later do cam install and larger intake valves.

Put the LQ4 in there with 5.3L heads with the larger intake valves and leave everything else stock. Of course dyno it and run it.

Put the LQ4 in there with the 5.3L heads, larger valves, heads milled .015, and a larger cam. Of course dyno it and run it.

 

I am sure it is probably much eisier to change the heads while the motor is out. But.... Running it stock and then changing the heads would give a real world example on the dyno and at the track for people considering the 5.3 heads.

I am curious myself to see how well the 5.3 heads do on the 6.0. Not sure if I have seen anyone do it here on the forum.

 

Those are all things I've considered. I'm up for many idea's as I'd like to be up for experimenting with it a bit. I'll also be running 93 octane or 105/E85.

 

I agree about testing but if you do please tell me the two piece front cover is out

the quicker its together the more tuning you can do...instead of doing the swap and tuning it and then changing everything and tuning it all over again. Who does your tuning anyway

What about an engine dyno? might get the desired info and save some work.

is this really for the wife or is this your new winter car?

 

No two piece covers for me. I bought it for the wife and need to keep it on the road for the most part. She drives my nice truck when the Hoe is down.

 

I could see doing #1 or #4 with a small cam, but I would do some pocket porting on the heads if #4. Isn't it funny how we even want our wife's ride to run hard? I swear it's a sickness.

 

If I do number 4 I have considered a little porting to make up for the 10cc difference in intake runners.

 

Questions to better help me understand your goals.


1) What 5.3L heads and what are the specs, if altered from stock?
2) What kind of time frame are you looking at to get this done?
3) What's your target compression ratio with that 93 octane?
4) Perhaps I missed this somewhere but what are the cam specs, if not LQ4 stock?
5) Don't get me wrong when I ask, why so much power for your wife? I mean, if she can handle the motor then all the power to her...I wish more women could.

 

So what's the deal, do you just have a 6.0 shortblock? I don't see the point of stock 5.3 heads on a 6.0.....choking it out?

I'd say LQ4 with LS6 heads, ported and/or milled if you wish. Then maybe TR220/224 cam?

 

Answers to some questions. I have an LQ4 long block on the way. The 5.3L head thing is something I am considering for the purpose of seeing the results from. I've seen some tests with 243's on LQ4's with nothing else changed and there is about a 20hp/20ftlbs of torque gain. I'm intersted to see if 5.3L heads make the same hp, but with more torque than stock. This isn't an idea to go fast with. What I want to do and probably will do around spring is just order up some brand new 243's from GM (not very expensive at all) and put them on there with a cam pretty much the same as my 5.3L. I'd like to end up with 11:1 compression, but will be happy with around 10:1. The cam specs at this point are stock, but I may be using this thing as a test mule so a few different cams might find there way in there. As for the wife, I could put a 408 with 10psi of boost and she'd want more. The time frame is a matter of how long I can handle her driving my 06'. As winter nears every thing from then on out will have to be a weekend project.