Project ‘Big Green’ 1985 Chevy K10: What Should We Do for an Engine Swap? [Poll]

1985 chevy k10 big green engine swap
1985 Chevy K10 “Big Green”

The 1985 Chevy K10 “Big Green” project truck is moving right along. We love the way the truck looks, but the power and sound do not match the mucho appearance. Simply put, Big Green is currently just too quiet and too slow.

Under the hood is a Chevrolet 305 cu-in V8, which (when new) produced around 165 horsepower and 250 lb-ft of torque. That was almost 32 years ago. “Big Green” was originally sold in Colorado, so the carburetor was jetted for high elevation. We use the truck at over a mile above sea level, where there is 17-25% less air density than at sea level. Needless to say, the truck is not quick.

The truck spent the last few years as a hunting rig, and the restrictive exhaust system is way too quiet. Other than that, the truck has the SM465 manual transmission that sends the power via the NP205 transfer case to 10-bolt front and rear axles. The truck has a four-inch lift and rides on 35-inch tires.

The truck really needs fresh power and a healthy rumble. We are looking at the GM Performance Parts crate engines for a possible swap. How much power can the driveline in this truck handle? Do we go for fuel injection or a carbureted motor? What about the transmission options?

Keep in mind, that we already spent just over $6,000 on the truck, when you consider tax, registration, insurance, and a couple of spare parts. We do not have a giant budget for this project. We cannot throw in a giant brand new motor into this thing and redo the entire driveline.

There are many questions to answer, and we hope you can start it off by providing your feedback on the engine swap. At this time, Chevrolet has 61 crate engine options, not all of them are “turn key” packages.

Please add your input in the poll below and in the comments section. Thanks!

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