How does it run? I'm planning almost the same install very soon on my '04 lb7!! I'm still trying to figure out what head gasket thickness to run after milling my 799's .030. What are the advantages of the cometic head gaskets vs. an mls gasket?? I'm still working on my 799's to get that little extra as soon as i'm done its all going on. What springs did you run??

 

I ran a .040 gasket, I was going to run a .030 gasket but the guys at TSP were nervous about my head to piston clearance.

The 243's were off of a LS6, so they have the "yellow" LS6 springs good to .570.

The cometic gasket is a MLS gasket, just have a thinner middle layer than OE. Honestly, I picked cometic, because they were the first ones I saw that had thinner gaskets, and I knew I could get them from a sponsor.

My compression is 9.89:1 according to Richard @ WCCH's calculations, up from the original 9.5:1

It makes more power everywhere than before, pulls hard from 3500 to 4500 and runs like a raped ape from about 4500 up with the cam, and I'm sure that will get better with the retune, especially since I'm going to move my shift points @ WOT from 5700 up to probably 6200-6300.

I haven't heard anything back from Justin yet about my retune, sent him an email Thursday night. So I expect it'll probably be Monday or Tuesday. It's running really rich, especially at idle. I've put maybe 150 miles on it and I've already got a pretty good coat of soot on the inside of the tailpipes where they dump over the axle.

I ordered my Wideband O2 Friday and my Aeroforce Interceptor last night, so I should be able to see more as to what's going on with my engine when I get those hooked up.


The only complaint I have, is how loud it is... at idle, it's great, just a little rumble, you can really hear the little bit of lope in the cam, honestly, sounds almost identical to my mom's 69 Vette (350 HO, Same length headers into 4" side pipe), at 1100 - 1600, it's a deep hum, at 1800-2400 it's a 12" redneck glasspack sounding cackle under any amount of load. I'm definitely going to have to change my muffler situation, probably to a pair of 50 or 70 series, or a pair of magnaflow mufflers.

I'm running the stock stall, and 3.73 gears.

 

First off thanks for all the good info on how your truck is running, some guys just give little info after they put these things back together.

I've got big tires, 2600 stall, 4.10's so I'm kind of thinking 212/218, but I might go with the cam you have to take more advantage of my 799's. UNDECIDED

I have Nelson tune so I was going to call and tell them what I'm doing and have them send me an updated tune before I do the install, how close do you think they can get it over the mail, I don't have tuning software or anything of that nature, would like to learn how, but not in the budget right now. The tuning is my biggest problem with this install

 

I'm running fairly tall tires 275/55R20 (I think it comes out to be 34"... don't know for sure)

You're running a little deeper gear and a stall, so I don't think you'd have any problem at all running the 216/220 if that's the route you decide. I sent Justin@blackbear a message before I started, and he assured me other than some idle learning, the tune would be able to run the truck, just wouldn't be ideal, and he's right. It's not ideal, but it runs. If you're doing a mail order (I opted for the scan cable a couple years ago when I did it, I'm also over an hour away from a dyno), they should be able to get it much closer than the stock tune, that's for sure.

 

That size tire should be between 30 & 31".

 

And the riddle is solved. Thanks for the info!

 

I run a 28 inch 3in offset single in/ single out magnaflow. I love how quiet it is but its still loud enough to know its not stock

 

Did you run 5.7 ls1 bore size gaskets?

What if I mill .040 and run stock ls1 (5.7) oem mls gaskets (.051 compressed measurement). Can you get stock gaskets in thinner measurements?
If I want to use my heads on an lq4 in the future what is the max I can mill and still run on pump gas, I think I read .035 somewhere.

 

Yes, they're the 5.7L 3.901 bore gaskets.

I don't know if GM makes thinner gaskets than the .051, the cometics are 3 layer as are the GM gaskets.

If you were to mill .040 and run a stock gasket, you'd have the same results.