Just picked up an LT4 swapped '86 C10

Hey y'all, I just picked up a new to me '86 C10 Silverado with a '96 LT4 swap. Working through some issues with it, but the intent is to daily drive it so I can sell my newer truck & get rid of any car payments! Working on tracking down why I experienced massive oil loss (2 quarts in ~250 miles) without seeing or smelling burning oil. The front of the engine was wet so put new timing cover gaskets/seals in. Hopefully that helps.

Next up is fixing the amateur hour wiring job one of the previous owners did (i.e. turn signals only work when headlights are off). Anyway, glad to be here & I expect I'll be spending an inordinate amount of time on the forum as I work through everything.

Welcome. Clean looking truck.

Welcome, looks like a dang nice truck!

Welcome from the Texas Panhandle.

Welcome from Missouri.

Howdy from Ohio!

The LT4 swap is cool! That's not something that's common anymore at all. When I read the title, I assumed it was going to be a modern LT4 lol.

bucket said:

Howdy from Ohio!

The LT4 swap is cool! That's not something that's common anymore at all. When I read the title, I assumed it was going to be a modern LT4 lol.

Click to expand...

The LT4 is one of the reasons I was attracted to this one - not to mention he already did the 5/7 drop and wheels which saved me the hassle and expense

There's nothing quite like a sbc with flowmasters; having a little hot rod under the hood is also nice.

F51 LRS said:

Hey y'all, I just picked up a new to me '86 C10 Silverado with a '96 LT4 swap. Working through some issues with it, but the intent is to daily drive it so I can sell my newer truck & get rid of any car payments! Working on tracking down why I experienced massive oil loss (2 quarts in ~250 miles) without seeing or smelling burning oil. The front of the engine was wet so put new timing cover gaskets/seals in. Hopefully that helps.

Next up is fixing the amateur hour wiring job one of the previous owners did (i.e. turn signals only work when headlights are off). Anyway, glad to be here & I expect I'll be spending an inordinate amount of time on the forum as I work through everything.

You must be registered for see images attach

Click to expand...

Welcome from Oregon!

The turn signal issue is most likely going to be broken or bad grounds at either the harness ends or the light sockets themselves. I've had this issue on two different squares and in one case it was a bad ground connection at the rear right turn signal plug socket and the other one was a bad ground wire connection at the front marker light socket. They will work OK or maybe a little slow without the headlights on because it is a very small load needing to dissipate through the ground. Once the marker lights come on with the headlights, the bad ground connection gets overwhelmed and you end up with no current flow to actuate the turn signal flasher so the turn signal just stays locked on. I would go through and make sure all the big ground connections are clean and secure, then start going around to each light connector and check for continuity between the ground pin for the light and the battery on each socket. I bet you find one or more socket with a really high resistance or even an open ground circuit.

Welcome from Austria. Great truck.

Welcome from Wisco, and gorgeous truck! Thanks for making with the pics!

Cool stuff, enjoy the fun!

What is an LT4?

85K304SPD said:

What is an LT4?

Click to expand...

The LT4 was the special high-performance version of the new-generation LT1. It featured a slightly more aggressive camshaft profile, 1.6:1 aluminum roller rocker arms, lighter hollow intake valves and liquid-sodium filled exhaust valves, larger fuel injectors, performance crankshaft, higher 10.8:1 compression ratio and high-flow intake manifold (painted red) with extra material above the port available to allow port matching to the raised port LT4 cylinder heads. The LT4 was conservatively underrated at 330 hp (246 kW) and 340 lb⋅ft (461 N⋅m). It was introduced in the 1996 model year, for the last year of the C4 Corvette, and came standard on all manual transmission (ZF 6-speed equipped) C4 Corvettes. The engine was passed down to 1997 SLP Camaros SS and SLP Firehawks with 6-speed manual transmissions.

The LT4 was available on the following vehicles:

• 1996 Chevrolet Corvette only when equipped with 6-speed manual transmission (includes all Grand Sports) (Production: 6,359)
• 1997 Chevrolet Camaro SLP/LT4 SS 6-speed (Production: 100 for the U.S., 6 for Canada. There were 2 prototypes)
• 1997 Pontiac Firebird SLP/LT4 Firehawk 6-speed (Production: 29)

All 135 production engines for the Firehawks and SSs were completely disassembled, balanced, blueprinted and honed with stress plates. One in 5 engines was tested on a Superflow engine dyno. Every car was tested on a chassis dyno and then performed a 6-mile (10 km) road test.