Justhereforinfo

iTrader: (2)

I've got a stock ls1 shortblock at the machine shop right now, and once it's ready I plan to get some cheap 243 heads. My budget only allows me to freshen up the heads, and have them setup with the matching custom cam's springs. Possibly mill them to bump compression, but I can't drop a grand on a cnc job. I'll use the ls6 intake and a quiet exhaust.

This is a replacement engine for my 4.8 in a 2003 rcsb silverado, so it will be fitted to a 4l60.

It will basically be a stock ls6 engine with a FTI custom cam, ground for a truck. It's main purpose in life won't be to break any Dyno records or trap speeds. It will be to haul my fishing gear, surf boards, and get good gas mileage. But that doesn't mean I don't care about power, I want this to be worth my time. If I don't pick up 100whp I won't be happy.

How much power can I expect to make with this combo?

FASTFATBOY

iTrader: (23)

Impossible to answer without knowing the cam specs.

You want nice flat torque for a truck to pull with, dont get hung up on a peak power number, you want a high average number for a truck.

For the record, my stock LS6 made 385rwhp through a six speed. With a mild cam I should have no problem making 425 +

redtan

iTrader: (5)

Not going to come close to picking up 100rwhp with just a cam and milled 243 heads on a 4.8.

Going to need full bolt-ons, decent cam with aftermarket or fully CNC'd 243 heads and a FAST to get 100rwhp out of that thing.

smws6ta

iTrader: (5)

^^
This or by spraying a **** load of N2O.

Justhereforinfo

iTrader: (2)

I think you misread my post. Stock ls1 shortblock, 243 heads, ls6 intake, custom cam, quiet (restrictive) exhuast.

A stock 4.8 puts down 225whp. Theres no way in hell i wont make at least 100whp +.

The other poster pretty much answered my question. If a stock ls6 motor puts down at least 350/350 to the tires, With a cam ground for my needs I should be satisfied with this setup. Its primary use is being a truck, but I also want to raise a little hell with it.

Justhereforinfo

iTrader: (2)

To clairify, its a 5.7 ls1 shortblock. I dont consider the 4.8/5.3 a real Ls1.

camarochvy21

iTrader: (4)

I think maybe 50-60rwhp. Heads are gonna kill te setup, but a step up from a 4.8 to a 5.7 should bring you closer to your goal

redtan

iTrader: (5)

Oh yeah, if you're going from a stock 4.8 to a new LS6 with a cam and milled 243s then it's going to make alot more than 100rwhp. The new engine should be close to 400rwhp which is almost twice what the stock 4.8 puts out.

FASTFATBOY

iTrader: (23)

How are the 243 heads gonna "kill the setup". You guys read too much internet ****.

The 243 heads will make him nice torque early on which is what he needs. This is why the heads come on trucks now.

243/799 is IMO the best cathedral stock casting head. I could pull my heads off, mill them to get 11.5 to 1, put 1.8 rockers on, put a pulley on, put a ported throttlebody on and make 400-405 to the wheels, all the while driving and sounding like a stock car. Put a FAST 92/92 on and make 410-415, put a cam in the car and make 450 to the wheels. It aint rocket science, all those numbers have already been done with a LS6.

My car ran 115 MPH weighing 3850lbs, he should be able to run 110 MPH with his setup in a 4200lb RCSB truck depending on DA and converter setup.

So how are the heads a "killer"?