I'm almost done building a stock ls6 using take off parts and a rebuilt ls1 shortblock. It will be essentially an ls6. 5.7 liter, zo6 cam, 243 heads, ls6 intake, tb, and 28# injectors.

My question is regarding the cam and intake. They were spec'd for a lightweight corvette, not a 4500 lb truck. I'm worried I might end up with not enough low rpm torque to get the heavy truck moving, and have all this high rpm horsepower.

Does anyone have this combo in a truck?

Please don't tell me I should have gone 6.0, unless your sending me one, or paying the bills. The 5.7 is what I had, which is much better than the 4.8.

 

it will run great! get a custom tune and you will be pleased

 

The LS6 is a proven MILD combo. It will have plenty of power. yes that cam is a little soft off the bottom, but a converter will really help you. To keep with the mild and budget friendly version I would suggest one of the name brand restalled trailblazer converters. FTI, circle d, and yank going from cheapest to most expensive in that order. Something around a 3000 would really wake it up. The combo of the LS6 with a 3000 converter would be night and day compared to what it was replacing (I assume a 5.3?). The converter is the last piece of the puzzle that I wouldn't skip though. It will make as much if not more of a SOTP gain on the street as the engine itself. I would even venture a guess to say that in a RCSB that mild combo would be good for low 13's in the 1/4 mile (depending on gears and a few other factors).

A more aggressive cam will require stiffer push rods, and springs, which would mean spending about another $700 for new parts. That being said you could create a cam that will deliver stronger off idle performance, a more meaty mid range and still offer as much if not more overev as the LS6 cam. The sacrifices will be made in idle quality and some MPG though. A cam selection is really a game of give and take. There are a few main things that people take into consideration when designing a cam: Idle quality and manners, MPG, low end TQ, and HP. The factory cams are always concerned with idle quality and MPG. To that end, if you are less focused on those things and are willing to make sacrifices you can gain more power.

 

Yea, i figured evvn with the stock cam it would be a vast improvement over the 4.8 in there now. I definitely will be get getting a converter, but I'm not sure what size or brand to go with. I too was thinking around 3000 since I don't tow.

Couple questions.

Can I use my stock truck coolant lines and fuel rails on the ls6 intake?

What else would need modifying in order to run the truck accessories on this ls6?

 

I'm not sure you can use the LS6 intake with the truck accessories... I think it will get in the way.

If it was my build I would find a 87mm truck intake from a TBSS or a 2007+ truck. It should offer you more bottom end grunt than the LS6 because of its longer intake runners, and make just as much high end HP if not more, and it will fit with all the other stock parts. You should be able to pick up one complete with the throttle body, and flex fuel injectors (32-36#) for $250 or so with fuel rails. Depending on the year of your truck you may need to get a 90mm cable throttle body and sell the DBW throttle body the intake comes with.

As far as the converter... that's really your choice. I love the Yank I have in the truck... but thats a $1100 triple disc billet converter. For the budget 278mm I think they are all fairly similar. The FTI is only 300 shipped on Jegs. People rave about the circle D though, and Chris is a really awesome guy.

 

It will work just have to get ls1 water pump and 3/4" spacers for the pump, and an idler relocation bracket. I'm using all my stock truck accessories besides the water pump. I have a 02 Ls6 5.7 in my 04 rcsb. Did away with the stock cam and did a comp 224/230 and love it. My truck stock was a 5spd with 3.73's though. Might be a little different with auto.

 

I'm pretty sure that the displacement will make up for and low end losses compared to a stock cam in a 4.8

 

Id sell that ls6 intake. They still go for $300-$400. Run the 78mm truck intake. It flows just as good. And its plenty for a stock cam engine.

Roll the intake money into a good converter. A single disc yank goes for around $850.

 

While I know that the single disc yank is a great converter... nothing about that says budget. If OP finds it in him to spend that cake on a converter then more power to him, but for a budget go fast build I would stick to the 278mm converters.

 

Well, you're right. But, if he gets what the ls6 intake is worth, it will make the yank more budget friendly.