Is the VIN on the heads or block anywhere? I assume not since it was said there is no way to tell by looking external...
Now the external physical size is the same as the 4.8/5.3 blocks correct?

Will the accessories and front brackets (water pump and all ) exchange between them...
Not trying to jack the thread just checking.
Dave

 

It is not on the heads or block. Both LQ4 and LQ9 use the 317 heads (unless it's an older on with iron heads), and I believe the block casting numbers are the same as well.

External physical size is the same as the 4.8 and 5.3, and yes, all the accessory brackets will interchange.

 

HUH
How do they know its a LQ4 and not a LQ9? I've never heard of such a beast.

 

Apparantly *some* early '99-'00 2500LD's came with flat-top pistons.....I discovered this when I did my head swap and had flat-tops, Jerry2500 on here is another one with flat-tops in an early LQ4. I don't know if the reason to do this was based on application or if it was just something GM did....I have never been able to confirm if this was done for a reason because if you go to a dealer and look up pistons for my motor it lists both flat-tops and -7cc dished pistons as appropriate for the motor

 

Im thinkin of going with a lq4 and having the blocked honed for some forged pistons. Stock rods and stock crank. and then sliding a cam, ARP bolts on everything, CNC my 5.3l heads, and few other nic nacs.

 

Interesting, good find.

 

Sounds like a good plan.

 

5.3 heads on the 6 liter?

 

with teh little research I have actually done that would raise the compression. Which on a N/A with nitrous as a possiblility I would think this would actually be good. Keep in mind they wont be stock they will have some headwork done by a local perforamcne shop.

Any reasons why it would be better to stick witht eh 317's on the 6.0?

 

3174's flow better, and have larger valves, but I havent figured out yet if the lowere compression and higher flow is better than the less flow higher compression. Ive been trying to find out though.