just as the title says....do 6.0 or 5.7 heads fit on 5.3 bore??

i know the 6.0 has a bigger combustion chamber,

but it also has 2.00/1.55 valves

would this fit,..... and would this help?????

sy0569

 

yes it will fit
yes it would help if they were milled to bump up compression or to get it back to stock.

 

physically..yes theyd fit.
will they work... yes, with a lot of modifications. and depending on camshaft
lift/duration profile, the valves may strike the cylinder edge. especially the
intake side.
the 6.0L heads have 71ish chamber size. to get them down to the 5.3 size
62ish thatd be alot of "shaving" about .075". the decks on these arent that
thick to be removing alot. sealing is already a b*tch...
the 5.7 LSx heads can be also used, but again .030-.050" shave to bring 'em up
to your 5.3 isnt exciting nor worth the gain.
stuffing larger valves into the 5.3 and using as such can be done, but the intake
side would be shrouded and cause some flow problems...
this is why the fbody peeps like the 5.3 as they can unshroud them with a minimum
loss of flow rate. and still increase compression.

airdeano

 

thank you yery informative!!

 

Upgrade your stock valves to LS1 size intake ports, get a good valve job and mill them .045" Its worth it. Trust me.

 

Are you saying to go with bigger valves like 2.02 or to somehow make the ports bigger? What is your CR with them milled .045?

Thanks

 

Milling the stock heads .050 will give you 10.3:1 compression. You can just stuff stock 5.7 valves into the stock heads. Milling is only about $50 per head.

 

4.8T put stock LS1 heads on his 4.8L and it had much better top end with no real loss in bottom end. Logging showed it was pulling 2-3 more lbs. of air also. I think stock LS1 heads milled .050 would be ok and make power.

 

ls1 heads on a 4.8...... same bore longer rod shorter stroke.

correct??

so in theroy they would work.

im also thinking of going boosted soon.

 

I thought that the 4.8's used the same cyl heads as the 5.3's