GnatGoSplat

Sorry if this has been discussed before, but I keep getting "SQL Error" every time I try to search.

Anyway, I have the 4.8L in my 99 and would like a little more power.

I have been thinking of:
A) Buying an LS1 or 6.0L block, crank, pistons, etc. and reusing whatever I can from my 4.8L.
B) Buying a complete 6.0L HO (complete LS1's a bit too expensive).

What would be the better option, starting with a complete engine or a block? I know starting with a complete engine is much easier, but I'd also like to do this for the most reasonable cost, and starting with just a block also lets me choose engine internals if there happens to be stronger internal parts available.
What would be better to use, an LS1 or 6.0L? LS1 block weighs less, and from what I've heard, is plenty strong. It should have good torque using the 4.8L's intake parts, and should fit right in if I use the 4.8L's accessories and such, correct?
However, the 6.0L has slightly more displacement, and iron is stronger than aluminum.
Is the weight difference between LS1 and 6.0L even significant?
I might want to add a supercharger someday, if that makes any difference.

Last question, how much of my 4.8L should I reuse if I start with just a block? Upper intake? Lower intake? Heads? Front cover, accessories, etc.? Being a 99, I know I would want a different cam, and being a 4.8L, I know I'd want a different crank and pistons.

Hit Man X

6.0 HO vs the 6.0 regular isn't too much difference powerwise. Lemme put it another way, I wouldn't shell out the extra cash for it. LS1 is a good choice but cost a bit for for a long block.

What are your final plans for this motor?

If you got just a block, you can use the best of internals...but they are super costly still. $1500+ cranks, $500+ pistons, etc.

I'd do just a 6.0 with stock crank, stock rods with ARP bolts, and some good forged pistons. The stock Gen III motors are pretty strong in stock form and will easily make well over 400rwhp in stock bottom end. Also RPM's kill internals like rods.

EVIL

why not get a set of heads and a mild cam? probably cheaper and far easier.

parish8

iTrader: (6)

another vote for a 6.0. get a used 6.0 with knock($900) then do pistons and rod bolts. probably cost you about$2500 total. you can pick your compresion with the pistons(low for blower, high for NA/nitrous). toss a power adder on there later and be good for ~600hp if you dont rev it too high.

you could always do haeds and cam when ever you got the money but just tosing a 200shot on that set up above with some good exhaust would probably get you over 500rwhp.

Hit Man X

I would think the stock rods with ARP bolts would take about 6400-6600rpms or so...any more than that and I'd be scared. The stock crank is made of some sort of steel and insanely strong. Infact I haven't heard of anyone breaking one yet.

Either way, enjoy your super stout bottom end that is pretty much stock!

GnatGoSplat

Thanks for the replies!
I'm not really looking to drag race my truck, but I would definitely like some more low-end. My truck is a big heavy 4x4 ext cab, and although the 4.8L is fast enough to keep up with traffic, it kind of feels a bit small.

For the near future, I was thinking I would like to have a truck capable of a 14-second quarter. However, the truck is a daily driver so I'm hesitant to raise the compression much over stock - I'd like to be able to run 87-octane pump gas without fear of detonation.

Is there a better place to look for a knocking 6.0L besides Ebay?

Assuming I did find a good LS1 or 6.0L block for a good price, are my existing 99 4.8L heads and intake good choices to use on it? They haven't changed, have they? I know the cam changed and I wouldn't reuse my old cam, but I'm not sure on anything else.

Hit Man X

Your truck heads on a LS1 or 6.0 will bump your compression to 10.5:1 or higher! Truck heads flow well but compression goes up, 6.0 heads are just slightly different versions of the LS6 head, the 6.0 ones outflow the LS1 ones also.

87 octane and boost or high compression won't work.

Check local truck boneyards for a complete 6.0 also.

GnatGoSplat

I see, so if I get an LS1 block, I'd want to use LS1 heads as long as I want to run 87 octane.

So 4.8 and 6.0 heads are different? Is the LS6 head a high compression head?

Hit Man X

Haha, no sorry about the confusion. LS1 heads + block with standard pistons = 10:1 compression...not 87 friendly.

4.8/5.3 - Small chamber, good for NA with small bore, smaller valves
6.0 - Large chamber, good for FI, good for larger bore not for smaller
LS6 - Smaller chamber version of 6.0, lighter valves, best overall head
LS1 - Medium chamber, good allover head, same valve size as 6.0

6.0 + 4.8/5.3 heads = very high compression, no blower, 93
6.0 + 6.0 or LS6 heads = blower happy and 87 friendly compression
6.0 + LS1 heads = slightly more compression, better for N/A, 89-93
LS1 + 4.8/5.3 = high copression, no blower, 93
LS1 + 6.0 heads = lower compression, blower and 87
LS1 + LS6 heads = slightly more compression than stock LS1, no blower, 93 only

That is what I think...anyone feel free to chime in and help out.

Tokez420

good info Hit Man