Chevy Engine to Jeep Conversion

by Richard Rowe

Chevy V-8 into Jeep conversions have been popular for generations. It almost seems like a no-brainer; simply install the biggest and cheapest V-8 out there into one of the smallest and most versatile off-road vehicles ever made. At the end of this well-traveled road is a go-anywhere buggy with the heart of a true hot rod.

Selecting an Engine

Jeeps in general (especially older YJs and TJs) are prized for their simplicity and function-over-form aesthetic, which makes installing a big V-8 in place of the vehicle's stock four-cylinder a matter of time and choice. Yes, a big-block Chevy will fit between those flat fenders, but you'll probably regret it. Big-blocks are heavy and expensive, and the extra torque they produce is somewhat wasted in a light and low-geared Jeep. Compared to even a 350 or 383 small-block, you're really not getting much in terms of trade off for the big-block's disadvantages.

Transmission

You can buy an adapter kit to fit the small-block to your stock Jeep transmission, but don't bother; the T-4, T-5 and 999 manual transmissions used in most Jeeps will explode into shrapnel behind the V-8's grunt. You be dollars and days ahead just swapping out the stock transmission for an automatic TH350, TH400 or a 700R4 (if you need overdrive). Using an overdrive transmission will let you run 25 percent higher rear-end gears, which should easily make up for not using a big-block.

Drivetrain

Your stock drivetrain was strong enough for the Jeep's original four-banger, but it probably won't last long behind a V-8. Well, it might if you never take the Jeep off-road, but then what's the point? Replacing the axles with something heavier duty will buy you some peace of mind on the trail. You should be able to get away with a Dana 44, Ford 8.8 inch or GM 8.5 inch on the front (since no more than 50 percent of the power will ever head that way), but go with a Ford 9-inch or Dana 60 for the rear. The stock transfer case may hold up for a while, but you should really consider installing a stock transfer case (like the NV4500) from any 4WD GM V-8 truck. Thank GM's bean counters for the fact that the TH350 and 700R4 use the same transfer-case pattern, which makes transfer case selection a matter of budget and not of necessity.

Conversion

While Chevy V-8s aren't exactly bolt-ins, they're the closest thing you'll find for a Frankenstein swap like this. Transmission and engine mount adapters abound, as do application/engine-specific exhaust headers and radiator hoses. You can even buy a large-capacity, V-8-ready radiator to fit the Jeep grille. While you can count on a certain amount of fabrication, it will amount to far less than with most swaps, if you buy the right parts.

About the Author

Richard Rowe has been writing professionally since 2007, specializing in automotive topics. He has worked as a tractor-trailer driver and mechanic, a rigger at a fire engine factory and as a race-car driver and builder. Rowe studied engineering, philosophy and American literature at Central Florida Community College.

Photo Credits

  • photo_camera jeep-safari image by Arkady Chubykin from Fotolia.com