Elijah Scott's 1971 Imperial LeBaron

Engine and Transmission Rebuild

Imperial Home Page -> Imperials by Year -> 1971 -> Elijah Scott's 1971 Imperial LeBaron -> Engine and Transmission Rebuild
Chrysler & Imperial Approved Service Imperials have always been powered by large, smooth, powerful engines, coupled with strong, durable transmissions. In 1955, when Imperial officially became a separate make, the engine was a 331.5 cubic inch hemi, producing 250 horsepower. The next year, the size was enlarged to 354, and the horsepower rating was 280. After that, Imperial engines continued to grow in size and power -- 1957 saw the introduction of the 392 hemi; in 1959 the 413 wedge head was introduced; and in 1966, a 440 cubic inch engine was made available for Imperials.

In 1971, the 440 available in the Imperial was officially rated at 335 horsepower, down from the 350 horsepower of the previous year. This page shows how the 440 in my own 1971 Imperial was modified to improve both economy and performance.


When I first bought this car in 1988, it had 131,000 miles on it.  Not long after buying it, a Chrysler dealership did a ring job and valve job on the car, which sort of helped it limp along for a while.  By 1997, however, with over 200,000 miles on it, it was time for a complete engine and transmission rebuild.  In February 1997, I was lucky enough to locate a true craftsman in the Knoxville, Tennessee, area to tackle this job.


engine11.JPG (76516 bytes)

The goal of this exercise was simple:

<--I wanted to go from this . . .

. . . to this -->

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 Now, with time, patience, and a lot of work on the part of a true craftsman, David Osborn, my Imperial was about to receive the treatment it deserves! 

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Yes, it's a very sad, tired engine, but it's in good hands! engine4.JPG (94763 bytes) And everything under the hood is mostly original, and not too bad for 200,000 miles!
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Dave didn't take long at all to get the car up on jack stands and . . . whoa!  Where's Waldo???

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That big engine compartment sure does look empty . . . and dirty!

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And speaking of dirty, the poor 440 looks like it's been sitting in an oil bath!  26 years and 200,000 miles of sludge and crud haven't done any favors for the appearance of this power plant.

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So this is the starting point . . . and that 727 transmission doesn't look so hot either!  Fortunately, Dave is just as handy with transmissions as he is with engines.

engine17.JPG (98001 bytes) engine18.JPG (90432 bytes) The engine bay is starting to look a little cleaner . . .
. . . And the transmission suddenly looks GREAT! engine22.JPG (68725 bytes) engine23.JPG (64771 bytes)
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NOW we're getting somewhere!  New pistons, re-machined heads, a new cam . . .
engine24.JPG (73754 bytes) engine25.JPG (83165 bytes) Not to mention some freshly cleaned and painted accessories and manifolds!
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It's all coming together!  What a GREAT looking engine, especially compared with where it started.

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And at last, the finished product, back in the car and back on the road!  Every time I drive the car, the performance of this fine engine brings a smile to my face -- it was worth every penny of it!

The engine and transmission rebuild was completed on March 15, 1997.  Obviously, this was a pretty big project!  For those of you who may be contemplating a similar project for your own Imperial, here's a basic breakdown of the costs for labor, parts, etc.

1971 Imperial LeBaron Engine and Transmission Rebuild

R&R Engine & Transmission; Replace Steering Gear and Coupling

Overhaul Transmission: Replace all seals & rings, clutches, plates, kickdown band & rear band

Overhaul Engine: Replace pistons; bore block .030 over; replace rings, rod & main bearings; turn crankshaft 10-10; replace oil pump, camshaft & cam bearings, timing chain & gears, drive gear bushing, and lifters; grind valves and replace guides; surface heads; install new carburetor, Mopar Performance electronic ignition, and fuel pump.

Cam Specs:  Competition Cam Part # 21-213-4

Gross Valve Lift: .440

Duration at .006: 260

Duration at .050: 212

Lobe Lift: .2933

Lobe Separation: 110


Transmission Kit 68.77   Competition Cam (Specs) 115.85  

Additional Parts

Flex Band 21.00   Oil Breather 15.00  

Summit Racing

Rear Band 21.43   2 Grommets 5.90  

Mopar Electronic Ignition


Filter 3.45   Transmission Mount 17.30  

Carter Competition AFB Carburetor


8 Pistons 264.00   Steering Coupling 50.50   Advance Auto Parts
1 Set of Rings 43.00   2 Battery Cables 12.88  

Rebuilt Steering Gear

PA 3790207


8 Rod Bearings 32.00   8 Spark Plugs 9.08  

Mancini Racing

1 Set of Main Bearings 38.00   4 Belts 11.96  

MOPAR High Speed Starter



1 Gasket Set 40.00   2 Radiator Hoses 14.98  

Year One

1 Manifold Gasket 11.00   Fuel Pump 16.49  

Spark Plug Wire Separator Package



1 Timing Chain Set 24.00   Fuel Filter 2.69  

Transmission Dust Cover



16 Lifters 32.00   Motor Mount 5.99   Machine Shop


1 Oil Pump 36.00   Spark Plug Wire Set 25.99   Total Labor


1 Block Plug Kit 2.95   2 Exhaust Gaskets 1.98   Total Parts


1 Camshaft Bearing Set 14.76   Paint (Engine & Exhaust Manifold) 52.69   Tax


1 Bearing Lube 3.63   Hoses & Clamps 8.57   TOTAL


This page was last updated December 1, 2005.  Send us your feedback, and come join the Imperial Mailing List - Online Car Club.