You can safely bore the 5.3 block out to a 5.7 bore and then use off the shelf LS1 pistons, and basically have an iron block 346ci LS1 on a budget. You can also put a 4" stroke crank and have 383ci , for a few more cubs, but that takes more money.

 

Good luck with that oil burner, piston rocking ****. I have a 4.100 in my 418 and it eats piston skirts and the wrist pin is so far up into the oil ring and I will be happy if it only drinks 2quarts every 3K which I doubt it will be that little. You also have to remember with a long stroke engine harmonics are going to be worse and you will not be able to spin it really high and it have any longevity to it since the iron blocks(6.0s inlcuded) have a short bore, the piston skirts come WAY out of the bottom causing the pistons to rock alot and eat skirts. There is a reason no one builds a 394(3.901x4.125) or 392s(3.901x4.100). Do what you want it seems you are set on building an odd setup but as Im sure you know 99% or the "odd-ball" setups are oddball because they dont work as well as something comparable. Use my info for what you want but I have been there done that and would definately go with a 4" stroke or a stock stroke bigger bore and spin it to the moon if I did it over again. With that said I love the off-idle tq my motor had even with the 237/242 112 cam I had in it.

 

you can bore a 4.8/5.3 to a 5.7 and use LS1 hardware. . . same rods, same pistons, same crank. Then you'll have an iron LS1

 

I had a **** load of clearance issues with my 4.100 stroke crank when using a 6.125 rod, now with a 6.200 rod it would have been easier but that would shove the wrist pin even further up in the oil ring. In order for my 4.100 stroke to fit in my 6.0 block it took spacing the windage tray out about half an inch, cutting and modifying the pickup tube, grinding on the crank counterweights and rebalance, grinding on the wrist pin bosses, grinding/cutting on the pistons skirts, back-cutting the skirts, filing and smoothing those backcuts to blend in the with the wrist pin boss and LOTS and LOTS of measuring with feeler gauges to make sure I had the right clearances. Thus I say 4" stroke, not worth the extra hassle. FYI stock LS1 over-bore is 3.901 for when you are looking for pistons I suggest talking to Richard at WCCH he can get you some nice pistons and rods for a good price along with anything else you might need, he has been a world of help to me in my builds.

 

I thought you had a bunch of issues.

 

Technically you can't make a 5.3 any larger than 5.3. anything larger would make it a 5.4 or up.



Just had to say it.. sorry.

 

Yeah just a few

Those that I posted arent even all of it but I think my post gets the point across.

 

Thanks for the info. The motor will be in a weekend/nice weather car,not a daily driver. Not spinning it too the moon either, @ 5500-5800 it will be done.

 

Thanks for the tip, as I thought adding cubic inches kept the Liters the same

 

With a 4.00" stroke and MAX bore to stock 5.7 pistons would get you 382cid. Could be fun popping the hood to show people your "cam only" 5.3L. Not many people would suspect a stroker out of a 5.3L because it is so "oddball".