BlackHawkY2K

So I gotta question for my next project. Have an LQ9 6.0L longblock out of a 05 2500HD pickup. Cast Iron block with aluminum heads and intake. My question is, if I take the 6.0 heads off and put the 98-00 5.7 LS1 heads, intake manifold, and cam in it, can I expect the car to run with the factory tuning? I know I may have to upgrade the factory LS1 injectors to some bigger injectors, but has anybody ever done this swap or maybe a swap like this? Most people I've talked to, have either stroked the 6.0 to a 400ci+ motor and/or aftermarket heads and cam. I would expect it to run atleast half ***, seeing as how the only thing being different would be the bore and stroke, but the computer is sending the same amount of fuel and air into the same sized chambers (5.7 has 67cc and the 6.0 is 73cc). Mechanically its going to have a longer stroke, but is the timing any different in the two motors? If not, I really don't see an issue, but I'm just trying to plan out ahead, before I do this. I'd rather use a set of LS1 heads instead of the 6.0 heads that are on it, and save the 6.0 heads for a turbo setup. Anyways, if anyone could give me any advice, it would be extremely helpful.

~Jonny

12secSS

iTrader: (30)

In that year, only the Silverado SS recieved the LQ9. If the 6.0L is truely out of a 2500HD, it is an LQ4. You would be better off staying with the 317 6.0L heads, as they are similar to LS6 heads. I put an LQ4 in my SS and I noticed it needed to be tuned. After I street tuned it, it runs much better. It will run on a stock tune, but I would higly recommend that you get it tuned if you do stay with the early LS1 heads. If you cam or stroke it, do not run it on a stock tune.

Formula350

iTrader: (3)

You'll need to tune it for the extra displacement so the computer can compensate the air-fuel.