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So, 93k original miles on the truck with near perfect compression. All I did was a new coil, wires, plugs, MPFI injectors, K&N drop in filter, and a true dual 2.5 inch cat back with Thrush Turbo Mufflers. Truck is a K2500 with a 4L80, and 14 bolt rear.
The end result, 183.7 hp on a Dynojet 248. The graph is pretty messed up cause you can't lock a gear with the 98 black box ECU, so the truck down shifts and then up shifts trashing the curve. Even so the dyno helped with cleaning up the tune with EFI-Live. The torque graph was useless but if you do the math it looks like it peaked in the 240-250 range based on the horsepower to rpm. You can really see how badly the stock intake and manifolds choked this as the rpm climb considering the horsepower curve is flat.
End of the day, I'm pretty happy with 183.7hp as a starting point considering lifted 1500 4x4 trucks with the early 5.3 are in the 200-220 range. Installing long tubes, a marine intake, and a small cam from comp. It will never make the power that my Suburban does but if it breaks into the 240-250hp range I'd be really happy with it for what it is.
Not bad for what you have, but also makes the last L31 setup I put together and tuned seem like it has a good boost over stock.
Stock block 5.7 Vortec with the 395' marine cam, 1.6s, Tri-Y headers, stock 1-ton cats, muffler, and exhaust, through a 4L80E and 3.73 geared 10.5" 14-bolt. 2nd gear pull with the converter locked. The blue line was an attempt at a 3rd gear pull but the converter was unlocked and hit the 98 mph speedlimiter pretty quickly. It has a duramax fan blade and March underdrive pulleys as well.
been looking at 2 different grinds for this. Comp sells a series of torquey "4x4 Cams" as they call them for the 305-350 OE roller blocks. Figure that with a new set of lifters, pushrods, LS-Locks, and LS6 springs would be the extent of it. Unsure though which on to purchase between the smallest one or the 2nd smallest one.
2 concerns with the bigger one are whether or not the engine will have enough flow up top with the marine intake and headers, and secondly how tight the valve guides will be with the larger lift. No real experience with the old small blocks cause millennial problems.
I just don't want to play it save only to learn I could have gone bigger. Truck is basically a daily/highway-cruiser, but a little lope and solid 1st gear kick downs would make it more fun.
I had the 1st choice in my Express, but it was cut on a 110* LSA rather than the 111* that Comp specs. Power fell off before you hit 5,000 rpm. In all honesty save about $100 and the CRAP Comp cast core roller cam headache and buy the factory billet steel 395' Marine cam. The marine cam works with a completely stock valvetrain and has a noticeable performance and sound difference.
Stock heads are good for .480 lift with stock springs. Install a set of LS1 high performance beehive springs with proper retainers and you will be good to about .550 lift and no machining of the guides.
I have a 5.7 L31 in my S10, just did the marine intake and cam with .528/.532 112lsa
The cam and intake gave me around 80hp gain to the wheels
Setup is stock bottom with prob over 200k on it, stock heads with Comp 918 beehive springs, retainers, pinned rocker studs, 1.6 crane gold roller rockers, mid length swap headers, xr270hr cam, marine intake, 0411pcm, 4l60e with S10 4.3 converter, tuned with HP tuners
Stock heads are good for .480 lift with stock springs. Install a set of LS1 high performance beehive springs with proper retainers and you will be good to about .550 lift and no machining of the guides.
I have a 5.7 L31 in my S10, just did the marine intake and cam with .528/.532 112lsa
The cam and intake gave me around 80hp gain to the wheels
Setup is stock bottom with prob over 200k on it, stock heads with Comp 918 beehive springs, retainers, pinned rocker studs, 1.6 crane gold roller rockers, mid length swap headers, xr270hr cam, marine intake, 0411pcm, 4l60e with S10 4.3 converter, tuned with HP tuners
The OP is talking about a Gen 2 sbc, not an ls series engine.
The L31 is the code for the 96-00 5.7 Vortec. He's talking about the same motor I have. You can convert the spring locks to the LS engine locks to run the LS springs for mor lift.
The L31 is the code for the 96-00 5.7 Vortec. He's talking about the same motor I have. You can convert the spring locks to the LS engine locks to run the LS springs for mor lift.
The L31 is the code for the 96-00 5.7 Vortec. He's talking about the same motor I have. You can convert the spring locks to the LS engine locks to run the LS springs for mor lift.
I see. Wasn't sure thats what you where talking about. Carry on......
Gonna try this again. Shortys with an EGR delete and a Trans-Go HD2. Gonna hit the dyno and see how it goes. After that doing a full cam kit from comp with a new distributor and a 411 computer.
Side note. Painted the bumpers on it and got a cover.
If we really want to get technical the 288 from 1917-18 was the first small block but big blocks didn't exist yet so technically maybe they aren't small blocks. But for clarifications no 350 from a factory produced truck was a gen2.
07-08-2016, 04:40 PM
