4.8 to 5.3

[DJGlover7]

Hello,

 

I have a 2005 Silverado 1500 4x4 WT w/ 4.8 and manual 5speed. The truck currently has 236K miles.

 

I would like to remanufacture the engine to a 5.3. I have read that the crank shaft is different for the

5 speed application.

 

Can I put a 5.3 crank in my truck and mate up to my 5 speed tranny?

 

Thank you,

 

Dennis

[Doug_Scott]

I would think the difference will be in the missing location for a pilot bearing. Has there never been a 5.3 with a manual transmission?  Try checking with a shop that equipped to remanufacture a crankshaft and see if they can machine the crank for the pilot bearing. 

 

I have never looked into it, but, is the crankshaft the only change required?  I have read some stuff that says the 4.8 piston is different to the 5.3 to account for difference in stroke to maintain compression ratio by either altering pin height, or top of piston.  I have also read the 4.8 has a different connecting rod to make that adjustment.  

[muddkatt]

If you are wanting to make those kind of changes, why not just drop in a 6.0? It would be a lot easier than building a 5.3 from a 4.8 and have more HP and TQ. Cant be very many 6.0, 5 speed trucks...

[DJGlover7]

All,

 

Here is what I have heard:

 

1) The 4.8 & 5.3 blocks are the same. Casting even shows "4.8 / 5.3".

2) Tech specs show identical bore, different stroke. 5.3 is longer (duh).

3) The 4.8 crank mated to a manual has a "different" flange mating to the flywheel (this is where the info is needed).

4) GM never mated a 5 speed to the 5.3 (several sources support this claim).

5) The 6.0 should drop in (and I do like that idea), but can it mate up to my 5 speed ( NV3500 )?

 

Related question on the 6.0. Will all engine accessories from the 4.8 bolt onto the 6.0?