Nope only diff between a 4.8 and 5.3 is the stroke. 4.8=shorter stroke i.e small displacement.

 

Are you sure about that ??? Have you researched it? There are two different part numbers for them... And mathmatically it doesn't work out that the pistons have the same top. Try this
http://www.rbracing-rsr.com/compstaticcalc.html

Bore= 3.78
stroke= 5.3=3.622 4.8=3.27
Head gasket thickness= .052
Deck height= -.008
Piston top volume 5.3= 9cc 4.8=0cc
Cumbustion chamber= 62cc

Now try swapping the piston top volumes it doesn't work out


And here are the part numbers http://www.engineparts.com/newsstories/50.3.3.170.pdf

 

:yup: that is correct. I have both actually.

 

Isn't that a lot of work just to raise the compression? Are you going to mill the heads while their off? or do any head work?

Sorry, I'm just curious
I wish I could be there to help you out, not that you need it...... ok, ok I would just like to watch

I like to read about the work that you guys do but, Josh is a local guy and I like to keep up to date, and offer a helping hand whenever I get the chance.

 

Steve I figured changing the pistons would be a better route to go. If I mill the heads and swap out thinner head gaskets the quench will be to tight not to mention piston to valve worries. I'm gonna clean up the ports some while I have them off.

I'm lookin for the that mid 12 pass N/A. New tires new locker and higher compression with slight head work MIGHT put me there.

 

I have both a 4.8 and 5.3 piston in my room. one is slightly dished.