iv read a few things here and there i want to be different i know why and whatever but i want a 5.0 lsx just so i can say yea its got the little motor in it and still blow people away

my questions are would stock ls1 pistons work since they are .03 over stock 4.8/5.3 bore size

would i need to mill the heads to keep compression around 10:1

and are there any differences flow wise between a 4.8 and a 5.3 heads?

anyone please chime in im new to the ls world just finished my fist sbc swap and wanna tackle this animal next

 

Stock ls1 pistons will give you 5.7 if you use a 5.3 bc they have same crank.you need a 4.8 with ls1 pistons do what you want...I didn't do the calculation but I assume it will be close to 5.0

4.8 flat tops with ls1 bore should be at least 10:1

And no there's not any difference between 4.8 and 5.3 heads

 

A 4.8 crank is 3.268 so if you use a 3.85 piston you would get 304~ci. which will give you your 5.0L. If you use ls1 standard borepistons (.118 over) youll get 312~ci. which would be something just under 5.1L. Do some research and price checking to see what would be more cost effective for your bottom end. Plenty of sponsors on here do a great job porting the factory 5.3 heads and will far exceed the flow requirements for a little 5.0 on everything but a max effort situation. Figure out your goals, do some research and get a hold of some sponsors. Good luck

 

Would it he worth the expense to bore a 4.8 to 3.904" bore making a rev happy 5.1L?

 

Be the experiment and try it out! Would be interesting to see the results...

 

Well its an additional 600$ for the forged ls1 pistons plus boring plus rebalancing...

 

Im running a 3.905 bore Manley piston on a Gen4 rod and a 4.8 crank.
313ci. along with twin 61mm Turbos on Ethonal. I love large bore small storke motors.. Nothing like the sound of a LS motor spinning 8000rpm.

 

What are you doing valve train wise to support 8000+rpm?

 

Just say your 5.7 is a 5.0?

 

Youll spend a lot of money to have a smaller motor with less power esp the loss of torque on the street. Maybe on a forced induction setup may have less bottom end stress but you WILL spend a ton on valvetrain pieces to avoid carnage. RPM motors are expensive.

understand a "different" build and all but sometmes people get carried away with stories about short stroke motors high rpm fast blah blah
BTDT.
always wanted a 69 Z/28 til I drove a few. Biggest turd on the planet, sound good thats about it;or go drive a 5.0 mustang 2v same thing
Go bigger, always