5.3 with 4.8 pistons

[99MedBlueBird]

Hi, I'm new here. I don't have a truck but I am working with a truck engine, and that's why I decided to ask for your elp here.

Anyways, I'm getting ready to work on a 5.3 lm7 to put into my firebird. I plan on running milled 862 heads about .030. I'm thinking about installing 4.8 flat top pistons. To also help bump up compression. Ive herd these pistons will work and I've heard they dont. Do I need to get the 4.8 connecting rods too or can I put them onto my 5.3 rods? Thanks

[kerrige]

Yes they will work. Swap pistons and you good. You will want to check for ptv issues.

[skeet]

why not save some time and money and get a flattop 5.3 nnbs engine! but yeah it'll work

[99MedBlueBird]

I can't decide whether to get a ly5 or l33

[kerrige]

I can't decide whether to get a ly5 or l33

Ly5 has got flatops and better heads. Less miles more than likely too and better rods.

[99MedBlueBird]

Okay guys, what's the difference between all of the genIV 5.3 blocks? (LH6/LY5/LMG/LH8)

[kerrige]

The Vortec 4800 LY2 is a Generation IV small block V8 truck engine. Like its LR4 predecessor, it gets its displacement from a 96.01mm bore and 83mm stroke. The smallest member of the Generation IV engine family, it is unique in that it is the only member of that family that use in trucks that does not feature either variable valve timing (until 2010) or Active Fuel Management.
[edit]5.3 L
Vortec 5300
The Generation IV Vortec 5300 engines are truck engines that share all the improvements and refinements found in other Generation IV engines. At present, four versions of the 5300 are in production: two iron block versions (LY5 and LMG) and two aluminum block versions (LH6 and LC9). All versions feature the Active Fuel Management system.

Wikipedia is wonderful

[J Industries]

Wikipedia is wonderful

Ya you sounded like a genius for a second.

[WhiteLS1]

When building my 5.3 I had my 4.8 pistons bored and pressed on 143 LS1 rods, engine runs great in my 81 K5 with stock lapped 862 heads and fbody manifolds. Don't quote me but I believe the L33 flat topped pistons are the same p/n as the 4.8 flat topped pistons. Either way they will work, Good luck with you build.

[thirdgenbum]

When building my 5.3 I had my 4.8 pistons bored and pressed on 143 LS1 rods, engine runs great in my 81 K5 with stock lapped 862 heads and fbody manifolds. Don't quote me but I believe the L33 flat topped pistons are the same p/n as the 4.8 flat topped pistons. Either way they will work, Good luck with you build.

i don't believe so. the l33 had floating piston pins, where most 4.8's had pressed fit pins.