Carbureted LSX forum - another 6.0 question

Just got a 6.0 shortblock to replace my 5.3. I have some 243s that have been milled .030 and been cleaned up alittle that i am running on it. should i transfer these over to the 6.0 or get some 317s or l92 heads. I plan on getting a bigger cam than my existing 218/222 w/.595/.598 cam. tranny is a 2004r w/2400 stall and 3.42gears. What should i do? i am running a perf rpm and 670avenger w/vac secondaries. on my 5.3 the perf rpm feels alot stronger on the bottom end than the vic jr. i had.

just a heads-up. you will have to buy a new intake to run the l92s. if its in the budget i would. the 670 carb is small for the l92s also. you will have to pump alot of fuel when u slam the throttle with the big heads. some of the other guys on the forum could give some more detailed advice , but that is a good overview. good luck!

thanks, when i do this i don't want to leave anything on the table. My 5.3 runs great, very driveable. I want more though and not be as conservative as i was. But still has to be driveable with good vacumn. I might end up going t56 also.

Reuse the 243s if it is a LQ4 with dish pistons, a GM Hot cam would be great for what you want and the Performer will not hold anything back with that setup, a larger 750 would be a plus but the carb you have will not keep it from spinning 6800 RPM.

Zone is dead on. If it is a LQ4, run the milled LS6 heads. However, I suggest you run the cam you have and it will work great with your current 2400 stall converter. If you do not go to at least a 3000 converter, go no larger that 224@.050" on the cam or it will be a dog.

On the intake manifold, I would not switch to the Victor Jr. unless you run a 3600 converter or larger and a cam that is 230@.050" or larger.

I'm shooting for 500 hp will that get me there?

I'm shooting for 500 hp will that get me there?

Wow. I did not see that coming from your original post. In short no. To clarify, are you saying 500hp at the crank or at the wheels? If you are saying at the crank, that is do-able with either a big ass cam and matching parts ala Zones build or you can do ported heads and a milder cam like my build. Either way, you are going to need a higher stall speed converter and a real carburetor like a Holley HP 750. You will likely want some 4.10 gears too unless your car is insanely light like 2500 lbs.

If you are saying 500 HP at the wheels, you are either going to need some AFR heads or ported LS3 heads, an LS3 Victor intake and the correct aggressive cam, big headers, good rod bolts, 950 HP Holley. 500 at the wheels naturally aspirated is rare air for an LQ4. It can be done, but everything will have to be really right. Most guys at that level usually build a 400" motor.

At the crank

You need the Vic Jr, larger grind cam, 750 carb ect ect to get there and be ready to lose a bit of low end drivability, it isnt too bad with a larger converter.

You need the Vic Jr, larger grind cam, 750 carb ect ect to get there and be ready to lose a bit of low end drivability, it isnt too bad with a larger converter.

At the crank

Look up Zone's build thread and check out his videos at the track. That car is a monster for no more than he did to it. I think it is the quintessential LQ budget race formula.

If you want a more streetable formula, I like the ported heads paired with a 22x camshaft and a 3000-3600 stall. My car goes 11s in the quarter and I could jump in it and take a road trip. If you are more about the track, Zone's car is about a solid 1/2 second faster than mine in the quarter.