AnotherWs6

iTrader: (17)

I am having a member on here build an LS6 long block for me. By that I mean a stock LS6 cam with 243 heads off of a Z06, stock 5.7 aluminum block etc etc. Essentially a factory stock LS6. This motor is going in my 5,500lb Silverado pickup. I am leaning towards using the factory 5.3 truck intake manifold for two main reasons. 1 - Simplicities sake. Of course it will need to be tuned, but I'm taking the stock manifold, injectors and rail off and then putting them right back on the new motor. Simple. Easy and limiting the number of changes. 2 - I think that it will help with the torque curve, especially with a bigger motor. I do have a complete LS6 setup (manifold, rails, injectors, TB) however. What do you guys suggest going with?



Here are the dyno graphs from the Hot Rod LS Intake Shootout Article. The blue lines are for an LS1 manifold and can be ignored since that's not an option. The red line on the first graph is for an LS6 manifold and the red line on the second graph is for an "early truck" manifold. I am assuming that this is the same manifold that is currently on my truck. At about 5,000 RPM the LS6 starts to outpace the truck, but I don't think that I would notice that little bit of power gain and that the truck would - hopefully - be more torquey during light to mid throttle.

Again, I think that keeping the factory parts will make things simpler to tune. I do own HP Tuners but have never used it. I will however be using it to tune my truck. It just seems like I'd be better off sticking with stock stuff so as not to increase the number of variables/changes. And I'm hoping that my factory injectors and pump will be able to keep up reasonably. Am I on base with that?

Just looking for some general thoughts and input. I - like many of us I believe - haven't done any serious tinkering with these new-fangled LS motors despite having owned several of them. A typical small or big block carb motor would make a whole lot more sense to me, but not looking to go backwards in time.

codyvette

iTrader: (24)

If it's an early model truck, ditch the intake and get the tbss/nnbs intake. I paid 160 each for two of them a couple of months ago. Why waste the time to put a 5.7 together only to choke it out. Also, ditch that LS6 cam and get a drop in truck cam from little John or another vendor for much better mid range power. You may even gain a few MPG over the 5.3.

AnotherWs6

iTrader: (17)

I figured people would say both of the things that you mentioned - TBSS and different cam.

To be honest I'm only doing this because the parts are available. Really wasn't looking for a motor at all because my truck still drives great, but some parts came up and one thing led to another.... So this is happening on the cheap. And that's the only reason that it is happening. So talking about buying cams etc, I'm just not into it. If I hate it I can always change it down the road but I think that the extra displacement combined with my 3,200 RPM stall and 4.88s will get the truck moving just fine. And again, TBSS intake means new manifold, different injectors, finding a bigger cable TB. Money and complication for a guy who has never done any serious work on a fuel injected vehicle and has zero tuning experience. But I certainly understand your thoughts.

stevieturbo

either or really, whichever fits the easiest for you. The difference between them is negligible.

AnotherWs6

iTrader: (17)

Thanks. I'm just looking for opinions and maybe some real world experience. And I don't know if I'm being overly cautious about changing things tuning wise. I'm noob there. I don't know if my facyory intake setup will be able to keep up. Don't know what's involved with swapping to LS6 stuff either.