Say I had an extra 4.8 block laying around, bored it out to the bore of a 6.0, and built it with the 6.0 crank, pistons and stuff and tuned the PCM. Would it be just like swapping in a 6.0 or is that not possible with the 4.8 block? Are the blocks any different between the 4.8, 5.3 and 6.0 or are they the same (part number)? If that is not too feasible then besides the crank, rods and tuning, what else is there, if anything, to turn a 4.8 to a 5.3?

 

You can bore the 4.8 block out to 3.9 and run LS1 pistons, rods and crank. That would give you an iron block LS1 @ 346 CI.

 

the 4.8/5.3 share the same block, just the crank differs, if you wanted a 6.0 you could put in a ls1 stroker crank rather than a stock and have it bored over. That would give you over the 6.0 liter if desired. with a .120 bore it would be like a 382 it think. The cost of one of those stroker crank i think is the only reason nobody has done this. I have looked into it but i think it may be wiser get a forged crank and not as much bore.

 

To answer you rquestion, yes that can be done. Don't forget about the cam though, those 6.0's do have a little more cam to feed the extra cubes as well as a little bigger head.

I'm with them though, if your gonna go for machine work, you may as well make it worth while and bore it over a little more and get some forged pistons for it. A forged crank and rods would be a nice mate for those pistons, but now your looking at some big money.

 

So, what you are saying is it can be done but it is probably going to cost a lot more than I want to spend. What about just swapping in a 5.3 crank and rods? Do I have to have new heads and cam with doing that?

 

Why not just spend the money and get a crate 6.0 and supercharge it!

It would more than likely cost the same as all the machine work and parts required to do the 4.8 thing.

 

You can just swap out the crank and rods to make the 4.8 a 5.3, you can pickup up the ls6 cranks pretty cheap form different tuners, that would be a great low cost alternative to a stroker crank and still pickup some cubes.

 

To put 5.3 pistons in a 4.8 block I think you'de have to get some machine work done still.

 

correct me if im wrong, but i think the cranks are all the same for all ls1 type engines <4.8, 5.3, 5.7, 6.0>. the bore is the only thing that is different.

 

They all have different part numbers listed with GMpartsdirect.com

There is a thread in the internal engine section about the difference in cranks between the 5.7 and 6.0

https://ls1tech.com/forums/showthread.php?t=118105