Quote:
Originally Posted by Heavymetl
A cammed 5.3 with headers and a truck intake will run right with most "built" 383s at your local cruise night. I know you're shaking your head right now, and that's ok. I would have too a few years ago.
150k miles is nothing. In fact, thats about all I mess with. Getting one externally rust free is more important than mileage.
The LS makes plenty of torque down low and carries it over a much wider rpm range than a classic sbc. But I do agree, the classic SBC does seem to make more torque in the sub 2500rpm range.
When compaing the LS to old school, dont judge by driving a stock pickup truck. These engines respond to mods like crazy. Its also not "all in the heads" either. Rod stroke ratio, 55mm cam core, stable valvetrain components, COP ignition, low drag oil pump, replicated ports, long runnner intake, stable block, low tension rings, windage tray, etc etc. They're literally a race engine found in the junkyard. Thanks GM!
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Went from a L31/Turbo350 (with a quadrajet and HEI) in my Jimmy to a 4.8L/6L90. Clearly the 4.8L is not considered as a torque monster, but I have to agree that LS motors are best above 2500 rpm. With my L31, 2.52 first gear, 3.07 rear end, and 33's it took off hard and would just about do burnouts without the brake.
Going to the 4.8L that makes 40 more horsepower and 40 less torque, it has 4.03 gears, same rear end and tires. The L31 still pulls harder than this setup, until about 3k.
At 3k, the LS engine really starts pulling and will pull all the way to 6500 whereas the L31 falls on it's face around 5k without upgrades.
I did the swap myself and I think I have about $6500 into it total. That's $2500 for engine/transmission/harness, $800 np205 adapter, $600 for hptuners, $600 for fuel system, $500 for manifolds and exhaust, $200 intake system, maf, and $400 for electrical stuff. I could have bought the L31 for $2k and dropped it in an afternoon for about $200.