4.8 or 5.3? how to tell difference?
 

So i just picked up what i was told was a 5.3 motor. Obviously the block markings are the same for 4.8/5.3. The heads that are on it are 862. Again, the same for both. I popped a head off and they are flat top pistons. I thought that 4.8= flat tops and 5.3= dished. Correct? Exactly what are the physical differences internally between the two? The bore is the same between the two right? This is going into an old truck, i plan to use this to get everything set up and running, then stepping up to 6.0 (possibly stroked). Oh yeah, it will be boosted. Just want to know if everything external can be used on all three- 4.8, 5.3, and 6.0?

Thanks guys for any and all help.

almost everythings the same between all three engines. but I think the only 5.3s with flattops are the l33's which have an aluminum block.

if the block is iron, i would bet on a 4.8l. if block is aluminum, would be 5.3l HO motor. to be sure, just mike the bores to be sure. someone might have built an iron block ls1 with it. no telling its past. pretty much all three are identical externally. and if your boosting, u might wanna stay 4.8l. those motors love all the boost you can throw at them. at any rate, enjoy and have fun with your project.

Never mind guys. I just spun the crank with one head off, the front piston dont move up and down. rod broke or something. gonna slam it back together and take it back to the guy. get my dough back or im gonna put my fist through the back of his head. maybe both. told me it was a 5.3, and its broke! Sum bitch.

Ouch, I hope he refunds it to ya.

:jest: wow... we've seen too many people getting screwed over on buying engines lately huh?

good luck man, i hope that piece of trash gives you a full refund.

that sneaky bastard

He's going to be like, oh I didn't know the engine was completely destroyed, it came out of a working vehicle...

measure the stroke- with a digital caliper.


easiest way to tell if its a 4.8/5.3
3.26(4.8) 3.66 ( 5.3)

bs
 

i made a 3 hour drive to pick up what i was told was a low mile 6.0... picked it up and they guy said his buddy took it out of his truck for a bigger cubed 7.0 ls7 .. soo im like okey he seems to know a little bout these ls motors... got it home n noticed some rocker bolts were hand tight... i ended up taking a head off just to check it out(this is before i knew wut torque to yeild bolts were or else i prob never would taken the head off)... once i got the head off wut do ya know.. the engine is missin a whole fuking piston and has half a snapped rod still on the crank side... i put it all back together and drove fukin 3 hours back to his place and he just acts like a prick and gives me sum homo story bout the guy sold it bc he needed money and shortly after he committed suicide... end of story i got my money refunded(minus the gas money which is bullshit) and hes is still a prick faggot im sure.......