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In all my driving on 87 octane, I haven't heard a peep from the engine compartment that sounds iffy.

Yup. It's load. When I last set up the advance curve on my BB Chrysler I ran as much lead and total ignition as I could pile on, headed for the steepest hill in the city, and lugged it at part and full throttle, listening for knock and pinging. Took the best curve I could with very minor pinging under those conditions, backed it off a degree, and she ran, and runs, very strong. Without pinging. Decent gas mileage, considering it displaces 451 C.I. and a 750CFM carb. I tuned mainly for total advance at 2500 rpm. I think I settled for @ 36 degrees BTDC. Lead advance was @15 degrees. In this:

Definitely interested in your tests and results.

Wellll....I dunno about 11:1 not running 87 Octane. The first question I asked was what are the Lift and Duration of the 5.3's camshaft. The reason for the question was that a long duration cam naturally "kills off" compression due to the overlap. When you look at the fact that we're getting 355 SAE Net HP out of 325 Cubic Inches, that would suggest to me a radical cam "tamed" by engine management and VVT. I have a 2006 Chrysler 300C/SRT8, and it's putting out a conservative 425HP SAE Net out of 370 cubic inches. The camshaft is more radical than the one's found in the old 1970-71 426 HEMI, but it idles like a pussycat. Reason? VVT and Engine Management.

Sooooo....I'm the guy who started this mess. What I get from all this is that upon registering vibration due to knock the engine instantly retards ignition, but takes it's time (over @200 miles of driving) before it starts advancing it again. The next logical question, given these events, is: How much more lead and total advance will it allow if we run higher than recommended octane? Enough to produce MORE HP and Torque than stock? If running 89 will trigger more advance over time, will 93 trigger even more of it? Thanks.

Why would it make more HP and torque on 89 octane? Does the engine management allow more spark advance with higher octane?

I was reading up on our L83 engine on GM's website, because I wanted to know more about it. I'm fascinated by the fact that with 11.0 to 1 compression, it runs on 87 octane unleaded. I know it has engine management and direct fuel injection and variable valve timing and all that. But what I want to know is what are the specs for the Camshaft? I figure it has to be a high lift, and especially a high overlap cam. High overlap cams produce power at higher rpms but "kill" compression by their nature. That's probably why it needs 11.0 to 1 pistons. But I figure variable valve timing shifts it to produce better torque at lower speeds, higher HP at mid range to higher speeds, etc. Anybody have the specs on the cam?

I'm looking to protect the front end from the typical 15-20 mph low speed "I was on my cell phone. Sorry!" collision. I want THEM to pay, not me. I'm not looking to survive a 70mph full frontal crash. Okie dokie.

I just emailed them for info. Looks good.

Greetings: On the subject of front end crash protection, what would provide the best protection from vehicles hitting the front end of my 2015 GMC Sierra 1500? Who makes the best Bull Bar Push Bars or Crash Bars in this regard? I've seen and searched for a bunch of them, just want to hear your opinions. I don't plan on any altercations, but if someone hits me or I hit them, what would be the best protection for the Front End? My truck is black, an SLT with a chrome bumper, and I want to keep it low profile. Thank You.

Mine didn't come with the console. Yeah. Just did. Thanks.

Ah. Thanks, but I need 98241, which is for a 1500 extended cab. Appreciate it.

O.K. Thanks.

Sounds good. But, I just did a check on Ebay, and all the front and rear sets are priced at a minimum of 179.95. Where did you find them for 120.00 delivered?

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