4.8 5.3 max bore
it is possible to go 3.905, and use 5.7 ls1 pistons
but a .060 over bore works fine, apply what the machine work will cost to a 6.0 block
.060 will make 4.8=5.0 or 5.3=5.5
but a .060 over bore works fine, apply what the machine work will cost to a 6.0 block
.060 will make 4.8=5.0 or 5.3=5.5
I've taken an '01 5.3 block to 4", but it's a mild build, intended for modest RPM, (5800) modest compression (9.9:1) although it has been to 6500 a few times. Some say they've had problems taking the early blocks to 3.9", but the price difference, around here, between a used 5.3 and a used 6.0 more than covers the cost of boring, if you wanted to end up with forged pistons. And it is worth it, around here, because I live at 4500' elev., so another full ratio of compression is helpful and low-risk. At sea level, you might need to consider the effect of the extra displacement on your compression ratio.
Thanks for the info guys. I could have gotten a 4.8 block for free but now I see it's not worth it. I was running 10 lbs of boost on an ls6 and broke a ringland. Now I need to decide what I want to do as far as shortblocks are concerned.
I've taken an '01 5.3 block to 4", but it's a mild build, intended for modest RPM, (5800) modest compression (9.9:1) although it has been to 6500 a few times. Some say they've had problems taking the early blocks to 3.9", but the price difference, around here, between a used 5.3 and a used 6.0 more than covers the cost of boring, if you wanted to end up with forged pistons. And it is worth it, around here, because I live at 4500' elev., so another full ratio of compression is helpful and low-risk. At sea level, you might need to consider the effect of the extra displacement on your compression ratio.
i had a 4.8/5.3 to 3.9 bore and heistated to make over 450hp. it still runs and has around 60k miles now, but never spins over 6k and amkes around 450bhp
