Chevrolet, also known as Chevy, is a subsidiary of American automobile manufacturer General Motors. They introduced big-block engines in the late 1950s till late 2000s with large displacement to produce more power for pickup trucks.
Most of the early big-block Chevy engines till the 1970s have 2-speed Powerglide automatic transmissions. Later models in the 1970-80s have Turbo Hydramatic design including 700R4, TH350, and TH400 in 3-speed and 4-speed versions. From, 1990-till now, Electronic Hydramatic transmissions, including 4L60E, 4L65E, 4L70E, 4L75E, 4L80E, and 4L85E, are in the 4-speed category and 6L80E in 6-speed transmission. Allison 1000 is also a compatible 5-6-speed transmission with Chevy big-block engines.
I will help you find the best combination of Chevy big-block engines and automatic transmissions for interchange in your vehicles.
What are big-block Chevy engines?
American auto manufacturer Chevrolet introduced Big-block V8 engines in 1958-1959 to produce more power and displacement for heavy-duty applications.
They remained the primary power source for pulling pickup trucks and heavier cars till the 1990s when Chevy started making small block engines with significant power ratings.
Since then, several generations of these engines have been available in the market until the manufacturer discontinued their production in the late 2000s and is producing small block engines only. These engines have cast iron and aluminum alloy blocks and sizes varying from 300-600 cubic inches.
Best Automatic transmissions with big-block engines by Chevy
Being part of General Motors, Chevrolet has a significant role in introducing and developing automatic transmissions for automobiles.
From the development of the first big-block engine in the W series in 1958-1959 till 2009, Chevy introduced several generations of automatic transmissions to fulfill the requirements of its different cars and trucks.
It is a 2-speed automatic transmission compatible with Chevrolet models, including big-block engines from 1960-1970 for passenger cars. It has 2 gears only with a gear ratio of 1.7-1.8 for the first gear and 1.0 for the second one.
Therefore, it remained popular in racing cars and trucks due to its more straightforward and robust design until the development of 3 and 4-speed Turbo-Hydramatic variants.
You can still find its usage in retrofitted customized vehicles for racing due to its more straightforward to use nature.
They are easier to build compatible with any power rating engine. You will find expertise or workshops in local markets capable of developing this transmission. It has a robust design with fewer maintenance issues with time and reduced wear and tear.
Moreover, it has an efficient operation and a good ratio spread between the 2 gears available. You will find torque converters in many shapes and designs and at economical prices. People develop it for drag racing applications, and its cost can vary from $1600 to $4500 depending on the racing type.
Due to limited gears, it is suitable for vehicles with high power to weight ratio. If you want increased GVWR, you need to increase the horsepower (hp) significantly.
You have limited options of either full slow or maximum rpm regarding acceleration and speed on the highway.
Chevrolet TH350 is Turbo Hydramatic 3-speed automatic transmission compatible with big-block engines to replace Powerglide transmission in medium-duty applications.
Chevrolet and Buick jointly develop this design and its variants, including 350C, 375B, and 250. It remained in service from the end of the 1960s to the early 1980s until the development of 700R4 transmission.
You will find it compatible with big-block engines during the period and few latest models with slight modifications. It has 3 gears with a gear ratio of 2.5-2.55 for first gear, 1.5-1.55 for second gear, and 1.0 for third gear.
Reverse gear has a ratio of 1.90-1.95. It has aluminum alloy construction and an integrated bell housing shape.
All 3 gears have an even gear ratio spread for better speed control and smooth transitions or gear shifts.
It is easier to build up to multiple power ratings in an inexpensive manner. Its maintenance is easy, and no particular expertise is mandatory for the task.
However, it will need $1000-$1400 for its rebuilding up to a reasonable level that is economical. It is compatible with large block V6 and V8 engines besides small block engines.
It has a play at the end, causing the clutch drum to become unstable. You can fix it by placing a washer between the clutch and gear.
You will need to buy a good quality torque converter for better and optimal performance on the road. Furthermore, despite being obsolete, you will find it in Chevy vehicles and available spares markets.
It is a medium to heavy-duty 3- speed transmission compatible with big-block engines from the 1980s to early 1990s. It remains the only option for a long time in the category of automatic transmissions for bigger cubic-inches and hp rating engines.
The first gear has a ratio of 2.45-2.50, the second has 1.45-1.50, and the third has a ratio of 1.0. It has 3 forward speeds, longitudinal position mounting, and GVWR of 8000 lbs.
It has reliable and rugged construction, making it suitable for heavy-duty applications. However, it will cost around $400 to $600 to rebuild it.
It has most of the characteristics similar to TH350. It is compatible with big-block V6 and V8 engines besides usage by several other auto manufacturers.
It has a bell housing design to fit with the engine. It is suitable for heavy trucks with half a ton or above ratings and too heavy to use with passenger cars. However, you will find it pretty much expensive to build up for high hp applications.
Chevy will introduce TH400 with ZL527 big-block V8 engine in its upcoming 2022 COPO Camaro drag racing car.
Turbo Hydramatic 700R4
It is a 4-speed automatic transmission introduced in the 1980s by GM for use in all its brands, including Chevy cars and trucks to replace TH350. It has an overdrive feature and saves fuel economy by increasing speed and reducing torque on highways.
It is compatible with Chevy Caprice, Camaro, Corvette, and Blazer models from 1981-1993. It has aluminum alloy construction with tail shaft housing, and you can interchange it with TH350 in older engines.
There is a massive gap between the first and second gear ratios of about 1.43. It results in a loss of acceleration despite the overdrive feature. Besides that, it has good performance at low rpm and provides better fuel economy in EFI engines.
Its sturdy and rugged design made it possible in big-block and small block engines at that time and later on. It can handle about 500 hp to 550 hp maximum power, and by adding a good quality drum, you can go beyond 600hp.
The problems associated with this transmission are overheating when used with high-power vehicles with extensive usage and broken input shaft in initial versions. You need to install a transmission intercooler to resolve the problem; otherwise, it can damage its parts.
Auto manufacturer upgraded its input shaft from 27 to 30 spline to prevent its breakage problem in earlier versions. Other features in later models in 1986-87 are ring gear, oil pump housing, and auxiliary valve body.
It is expensive to rebuild due to its complexity and to improve its performance. It will cost you around $1500-$2000 to work it up to a reasonable level.
It is an electronic version of the 700R4 transmission introduced in medium-duty pickup trucks to replace its Turbo-Hydramatic counterpart.
It has all the features similar to the 4L60 except electronic control via shift solenoids and better GVWR of 8500-8700 lbs. Moreover, its salient features are better fuel average, no TV cable and shifting via electronic control, and low-speed performance.
It is expensive to build and will cost around $2500-$3500 depending on the level you want to achieve.
It is compatible with most big-block V6, V8, and Inline engines by Chevrolet. For vehicles without PCM or ECM, you need to buy a GM controller and install it for electronic control of the shifts.
It has 2 improved versions, 4L65E and 4L70E, with better features and after removing shortcomings of the previous design.
For example, it has improved planetary components and strong input shafts as compared to its predecessor. Moreover, it has higher power outputs to be compatible with newer generation engines.
It is a 4-speed electronic version of TH400 introduced in the early 1990s, suitable for heavy-duty Chevy trucks. It has 2 other variants, including a light one, the 4L80E, and an advanced one, Supermatic 4L85E.
It is compatible with vehicles having GVWR of 8000-18000 lbs by adding additional parts and increasing levels. In addition, it is compatible with Chevy big-block V8 engines, including Chevy suburban with 454 big-block engine and Avalanche with 8100 Vortec engine, to name a few.
Torque rating of 4L80E is 430-450 lb-ft, 4L85E is 450-470 lb-ft, and the Supermatic version has a limit of 680-690 lb-ft. Therefore, it will cost about $2000-$3000 to rebuild it up to a satisfactory level.
The common problem associated with this heavy-duty transmission is slipping or time lag when shifting between the first 3 gears. In severe cases, it can result in overheating, causing damage to the parts.
Supermatic 4L85E is the latest improved version compatible with all big-block engines. In addition, it has 4 evenly spaced gear ratios, additional clutch plates to increase torque limit, improved heavy-duty torque converters, and increased fluid pressure.
It is an improved version of 6-speed automatic transmission with electronic controls for heavy-duty trucks. You can connect it with Chevy engines using compatible parts like torque converters.
It is suitable for high horsepower applications providing maximum torque of 640-660 lb-ft. It is a relatively new design with high-performance parts compatible with compact LS and LSX crate engines, but you can retrofit with big-block engines by slight modifications.
Its rebuilding and installation cost, including the stall converter, is approximately $3000-$4000.
Allison 1000 transmissions are 5-6-speed automatic third part transmissions compatible with Chevy engines. It can handle torque up to 610-630 lb-ft.
It has standard features, including overdrive gear, torque converter clutch, and safety devices like a parking pawl to lock the transmission when the vehicle is in the park position.
Another innovative feature is adaptive learning of the transmission and tuning itself according to actual engine parameters. It ensures smooth and comfortable driving with no hard shifts. Moreover, it has a limp mode in case of any damage to the transmission.
It enables you to drive the vehicle in a single gear. The 6-gear version has double overdrive capability for the fuel-efficient performance of the engine.
It has the best combination with Chevrolet Silverado Duramax 6.6-liter V8 engines for medium-duty high torque applications at low speeds. You can also fit it with a 7.4-liter big-block 454 engine. However, it will cost around $2500-$3000 to replace the transmission in Chevy trucks.