1984 was the first year for the 200-4R transmission. Although it was associated originally with the troublesome 200C three speed transmission, the 200-4R soon developed into a fine unit. Used in applications ranging from full size Cadillacs to the powerful Buick Grand National, the 200-4R overdrive transmission is a proven Performer.

Our Custom Rebuilding process includes improvements such as:

Heavy Duty Shift Kit

Large dia. Throttle boost valve

SUPER DUTY front pump assembly

Large dia. servo

Hi capacity band for those tire chirping 1-2 shifts.

Another BIG plus is the fact that the 200-4R comes in a MULTICASE bellhousing making it available for use behind almost ANY GM engine. This is a HUGE advantage when constructing any street rod type vehicle. Add to this the advantages of a favorable set of gear ratios ( see our gear ratios section), the advantages of an overdrive combined with those of a lockup torque converter and you have all the good things wrapped up in one! Keep your driveline as well as your bank book intact with this one!



Beginning life in 1982 the 700R4 was GMs first attempt at a modern overdrive automatic transmission. Used in both passenger cars and trucks (both 2WD and 4WD) until 1993 when an electronically controlled version was introduced called the 4L60E. The 700R4 was available in two different bellhousing versions; a 2.8L V-6 version and a SB/BB Chevy V-8 version. A BOP (Buick-Olds-Pontiac) bellhousing was never available from the factory, however aftermarket adapters are available (Contact our staff for information).

We make many modifications and upgrades to this transmission, such as: 

vane pump rotor (replacing the Seven vane type).

Steel pump vane rings replacing the earlier cast iron type which often broke causing TOTAL destruction of the pump.

A larger 30 spline input shaft replacing the 27 spline shaft.

Hardened rear ring gear replacing the earlier breakage prone units.

A larger surface area
servo piston giving greater holding capacity to the critical 2-4 band.

Countywide units include ALL of these upgrades


Hi-Energy friction linings on the 2-4 band and 3-4 clutch plates for long service life.

The factory throttle boost valve of .320 dia. is replaced by our .500 super duty unit for MUCH quicker oil pressure rise under heavy duty use.

A heavy duty Shift Kit

A Hi Capacity dual spring oil pump

Combine all these modifications and upgrades and you have one of the STRONGEST Hi-Performance transmissions available for street or strip use and STILL HAVE MONEY FOR GAS!!!



The Turbo Hydramatic 350 began production in 1969 as the workhorse of the GM line. This unit was used in cars ranging from the light duty Vega up to the full size Caprice as well as some trucks. The TH350 was available in both 2WD and 4WD applications with either a Chevy or BOP bellhousing. 
Our TH350 transmissions have MANY modifications to ensure a long life as well as crisp clean shifts. 

Modifications include:

Full apply direct drum for extended High gear life

Extra wide drum bushing for greater drum stabilization and vastly improved ring sealing.

A hardened intermediate sprag race which eliminates the breakage so common in this area during heavy use.

Specially modified forward and direct clutch drums which give 20% more torque capacity than standard units giving you MAXIMUM holding capacity when you REALLY need it!

Metal sealing rings throughout

Heavy Duty Shift Kit

A Hi performance adjustable vacuum modulator

All these features make this a rugged performer at a GREAT PRICE




The Turbo 400 began production in 1964. It was used in the GM car and truck lines and has several bellhousing styles available to bolt up to the popular Chevy and BOP (64 and newer Buick, Olds, Pontiac and Caddy V8) engines. Also available was a rare bellhousing style to bolt to a Jeep. The TH400 has been used in vehicles as powerful as the 1970 Chevelle SS454 with the potent LS-1 Big Block. The 400 can take a LOT of power!

Our units are custom built with the following features:

Extra capacity clutch packs

Hi Performance shift kit

Heavy Duty intermediate sprag or roller clutch

Full apply direct drum (for improved Hi Gear shift quality)

Heavy Duty adjustable vacuum modulator.

All the materials we use meet or exceed OEM quality specifications. All this gives you, our customer, a transmission that is "Strong as an OX", yet affordable.