Truck Swap – LS Style! What it Takes to Swap in a 525 hp LS3 Connect & Cruise Package in a Chevy Pickup

Words and Photos By Jeff Smith

Adding power and performance is a very addictive prospect. Take Josh Garber and his ’71 Chevy C10 pickup. This truck has been through quite a bit. Its jungle-drum history began some years back with a bad-to-the-bone turbocharged big block that was nasty, but shaky on durability. Truck guys like their stuff to live, so the needle swung 180 degrees toward something a bit more dependable.

In went a previously-owned 2002 5.3L truck LS engine with a 4L60E automatic that, from all accounts, ran great but was a major departure from its powerful predecessor in terms of throttle response. You can guess what happened next. Garber had a yearning for a little more power. That’s when he sought out the engine swap masters at Galpin Auto Sports (GAS), in Van Nuys, California. After a short discussion, the obvious approach was to take full advantage of factory LS power — with a little spice sprinkled in. There was a budget to maintain, so the big-dog options like Chevrolet’s supercharged LS9 or LT4 engines were a little tough on the wallet.

The customer ordered a brand new LS376/525 engine and 4L70E automatic combination under Chevrolet Performance’s Connect & Cruise package. This system is designed to work together as an engineered package. The engine is a hopped up LS3 with a bigger cam, making 525 hp.

So, the choice came down to a strong, yet reliable Chevrolet Performance Connect & Cruise option. The decision landed emphatically in line with the 525 hp 6.2L LS3 crate engine backed with an equally stout 4L70E digitally-controlled automatic. After the big crates rolled onto the GAS shop floor, the wrenches started flying. The swap was not as challenging because there was already a 5.3L LS truck engine and 4L60E trans in between the fenders. The goal this time around would be focused on a more professional approach that would de-content the spitball welding and cheese-ball home plumbing heater hose fixtures. Maybe the previous builder was a plumber.

The project fell to GAS mechanic Manny Gonzalez  who had the old engine and trans out in a matter of an hour or so, The first thing he did was swap oil pans, removing the stock LS3 oil pan in favor of the 5.3L’s deeper truck pan that easily cleared the C10‘s stock crossmember. With that accomplished, the new engine and trans dropped into place, which immediately opened up a series of small issues Gonzalez had to solve.

While long-tube headers would make a little more power, the Holley cast iron LS manifolds fit nicely, minimize maintenance, and eliminate those annoying exhaust leaks from headers.

Even with the now 525 hp engine, owner Garber wanted a truck that would emphasize the fun side with minimal maintenance. While long-tube headers are always the way to go when power is a consideration, they opted instead for a set of Hooker cast iron manifolds for the LS3, since these would be virtually maintenance free, offer no exhaust leaks, and perhaps make a little more power than the OE versions.

Because there are so many different Connect & Cruise packages, Chevrolet opted to manage the electronic 4L60E transmission with its stand-alone SuperMatic transmission controller package. Hookup is literally a plug ‘n play affair, so the biggest obstacle was finding a place to nest the engine ECU, the trans controller, and the rather substantial fuse block. Gonzalez elected to place the engine ECU and the trans controller in the dead space directly between the front seats, underneath the deep center console. The fuse box ended up in the right front corner of the engine compartment, where it can be easily serviced.

Even with all the Connect & Cruise main part numbers, this is not all-inclusive kit. We’ve listed most of the major part numbers GAS included in this swap — with a substantial one being the engine’s front accessory drive. The engine is fitted with just its water pump and Corvette balancer. The rest is up to you. A few deliberations with the tape quickly revealed the factory LS3 accessory drive would fit, except for the A/C compressor, which intersected the engine crossmember.

A big part of a successful LS swap is including a good fuel delivery system. Among the best ways to go is with an in-tank submerged pump like this Aeromotive Phantom kit that can be easily retro-fitted to the stock fuel tank.

Instead of adapting a different mount o accommodate the A/C, GAS opted instead for a complete Holley LS accessory drive package. This allowed Gonzalez to retain the stock balancer while also relocating the A/C compressor high on the passenger side with the simple addition of an optional set of brackets. The entire system looks factory and runs the on one serpentine belt.

The GAS approach is to make each of their engine conversions look as factory as possible. We’d say they achieved that and then some. This is one LS376 that’s ready for the road!

This swap also demanded a new Griffin aluminum radiator, along with a set of Spal electric fans to keep everything cool. This still left enough room for a 4-inch aluminum cold air duct between the accessory drive and the radiator. GAS fabricator Eric Simpkins whipped up the simple cold air package that also accommodated the factory-required mass air flow (MAF) sensor, so that all the electrons could make their connections unimpeded.

With everything bolted in place, the engine didn’t fire immediately. It turns out there was a mix-up at the factory and the wrong ECU was shipped with the engine. Simpkins is also the head tuner and quickly discovered the error. Once the proper ECU was slipped in place, the LS376 fired immediately and now runs like a champ, living up to its Connect & Cruise moniker. Garber has since taken possession, and the truck is now tearing up the streets of the San Fernando Valley. Another GAS swap well done.

Connect & Cruise

There are three different Connect and Cruise packages available with an automatic trans that are based on the LS3 engine. The standard kit combines the stock 430 hp LS3 with a 4L65E transmission. The second version is a 480 hp upgrade with a slightly stronger HOT cam. The strongest option is the 525 hp version LS3 and a 4L70E trans and converter. This engine uses the hotter ASA camshaft. These packages are available from any Chevrolet Performance dealership or outlet.

Package Connect & Cruise Overall PN:

LS3 430 hp and 4L64E trans: CPSLS34L65E

LS3 480 hp and 4L70E trans: CPSLS3764804L70E

LS3 525 hp and 4L70E trans: CPSLS3765254L70E

Parts List

Sources: Chevrolet Performance; Chevrolet.com/performance; Galpin Auto Sports, Galpinautosports.com