I have a 5.3 I just tore down and want to bore it out before rebuilding. I have never built an engine before so this is all very very new to me.

I want to go with the same bore as a LS1, but I really do not know what the exact number the bore is?? I have read the JRP sticky, and in there I have found 3.898" and 3.900... I would like to get this done right the first time. I don't know what I should tell the machine shop to bore it out too because of this slight confusion. Or does it even matter? Could I just bore it out to 3.900 exactly (which is the max you can bore the 5.3 I believe) and order custom pistons, or would that be a lot more money?

Also, would it be wise to replace the connecting rods? I dont intend to use Forced Induction, just keep it all motor. They currently have about 40,000 miles on them.

Thanks in Advance!!

Nate

 

Are you trying to use stock 5.7L pistons? If so the stock bore size is 3.898. Most after market pistons are 3.903 or 3.905 because that is what people hone the block to when redoing the motor. I would do forged rods and pistons, and remember you need to balance the rotating assembly whether you stick with stock or aftermarket parts. The 5.3L can be bored out to 3.903 no problem.

 

Yes I had planned on using stock size 5.7L pistons so I wouldnt have to get custom made ones. so would it be able to hit the 3.905" mark or is that too big? Thanks for the info

 

If you are going to use the stock pistons then you would want a 3.898 bore size. 3.903 or 3.905 is the typical bore when going to after market forged pistons. People go through the cylinder with a clean up hone .005-.007 over stock on a typical 347 build up. The 5.3L can easily go .100 over. I would give your machine guy the set of pistons so he can measure them out. Otherwise 3.898 should be good.

 

best thing to do is have the machine shop get the pistons and then they bore it to the right size or you buy the pistons and give them to the machine shop so then there is no confusion, they can measure right from the pistons to get the right size

 

ok that all makes sense. Should I give them the rods and crankshaft all at the same time so the could balance everything? I should give them a call to find this out but I havent found a reputable shop yet.