Lm7 build
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Lm7 build So i just pulled my lm7 and planned on just swapping it out with a junkyard one for a daily but decided to rebuild it and try to get 400-450hp out of it looking for advice on where to start this will be my first time rebuilding an engine
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If doing a full rebuild, get the flat top pistons used in the 4.8. They bolt right in. You will then have 10.47:1 compression with no other changes. Get a mild truck cam as I suspect this is a truck engine. You don't want to lose too much low end torque.
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400 at the wheels is going to take a lot more than just a piston swap. 450rwhp is going to take a lot, if it's even possible. 400 rwhp is doable, but will take a full-on heads, cam, intake, but I get the feeling that you're going to lose a lot of low-end grunt (at least, compared to what you have now), which doesn't bode well for a truck. What kind of budget are you working on?
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400 at the wheels is going to take a lot more than just a piston swap. 450rwhp is going to take a lot, if it's even possible. 400 rwhp is doable, but will take a full-on heads, cam, intake, but I get the feeling that you're going to lose a lot of low-end grunt (at least, compared to what you have now), which doesn't bode well for a truck. What kind of budget are you working on?
2k budget you better leave the engine alone and save some more money... You could possibly throw a turbo kit together for that kinda money if you wait around for some deals to come up on used stuff. On a completely stock 5.3 (other than fuel system) you could get 450rwhp with less than 10lbs of boost .