Over the course of the last couple months, I’ve really fallen in love with driving my C10 around, especially now that it’s got the Holley Avenger fuel injection system installed as well as the power steering and resized steering wheel. It actually feels like a new truck and exhibits all the traits one would expect. This makes me feel a little hesitant, perhaps almost guilty, to tear it all apart to install a new LS327 crate engine from Chevy Performance. The stock 307 runs really strong and ticks over like a finely tuned Swiss clock and I’m a bit nervous to mess with such a reliable setup. But I’m a hot rodder at heart and it’s just not natural to ignore something better off left alone. Plus the power and reliability that the LS series engines offer is too tempting not to jump in the fire and experience it firsthand.
They’re called crate engines...
They’re called crate engines for a reason and when they show up at your doorstep, you’ll know why. This is how our LS327 looked once unwrapped, a pretty exciting sight for any gearhead.
When I started the ’68 C10 buildup back in the June 2011 issue, I had two different iterations of what I wanted to do. The first, which we’ve pretty much completed up to now, was to drop the truck and improve the handling and driving characteristics as well as overhauling the drivetrain and interior components to a restored-type status. During this initial segment, I didn’t want to deviate from stock too much when it came to the interior, exterior, or the engine compartment. That meant simple restoration upgrades like new weather stripping, window rubber and felt, a new floor mat, hood bumpers, etc., as well as cleaning up the engine bay and restoring the look back to a similar ’60s factory appearance. Though I did lower the truck and bolted up a new set of rollers, I left the bed long and didn’t alter the exterior appearance other than restoring the two-tone white on the cab and replacing all the brightwork.
But starting this month, it’s time for all that to change. I discussed in this month’s Haul Monitor what we’ve got planned for the Laggard Longbed build version 2.0, so I won’t bore you with repeating the details here, aside from the preliminary bit on preparing the LS engine and pointing out a few things worthy of mention.
As previously stated, the plan is to install a Chevy Performance 5.3L/327ci LS engine between the ’rails of the ’68, replacing the stock 307ci engine that came with the truck from the factory. Based on the ’99-06 series of GM truck engines, the LS327 consists of an iron block with a 96mm bore and a 92mm stroke, topped with the same production aluminum heads and hopped up straight from GM with a Chevy Performance cam and Grafal-coated pistons. With these simple upgrades, the numbers jump up from a respectable 295 hp/325 lb-ft of torque to a much more impressive 327 hp/347 lb-ft. What makes the swap to the LS really cool is all the aftermarket hop-up products available that can easily take the LS into the 600 hp and beyond realm. We’re not gonna aim that high right off the bat, but we may do something a little more radical in the months to come.
The first thing I’m going...
The first thing I’m going to do is to get the engine in some color. To do so, I carefully masked any openings as well as anything that couldn’t be removed (such as the crank snout and spark plugs).
I’ve had great luck with Summit...
I’ve had great luck with Summit Racing’s line of engine paint and it just so happened that I had some left over from shooting the original 307 that’s in the truck. Chevy Orange will give the LS that ’60s vibe visually, further complementing its similarities to the original 327 engines and their GM Black is a great overall coating for those parts that need a good satin black color with a little temperature protection to boot. Everything that will be getting sprayed will first get hit with Eastwood’s PRE painting prep to ensure that the part’s nice and clean.
After a thorough cleaning...
After a thorough cleaning and four coats of engine paint this is the end result. I installed the crossover steam pipe, spark plugs, and began removing the masking tape.
I masked the area around the...
I masked the area around the intake ports to make cleanup a little easier. I figured the gaskets would have a better chance to seal properly if there wasn’t any paint in the immediate area around each port. Also worth a note is the absence of any water passages at the top of the heads, one of the things that make intake swaps so much easier on the LS-series engines.
For the initial iteration...
For the initial iteration of the LS, I’ll be using a Chevrolet Performance four-barrel cast-aluminum intake manifold. This particular manifold is designed for the cathedral port LS heads and a 4150-style square bore carburetor.
I noticed a couple of things...
I noticed a couple of things right off the bat that were new to me as I’ve got zero experience working with the new LS-series engines. One, everything is metric, which required me to dust off those metric tools that I stashed away many years ago. The second was the low yield when it came to torque ratios on a number of the components, including the intake. Chevy Performance recommends an initial pass using 44 lb-ins on all the fasteners, followed by a pass of 89 lb-ins. Note that’s inch-pounds and NOT foot-pounds.