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2. Toyota 4 Cyl. to GM Bellhousing Adapter

Toyota 4WD engine conversions are extremely popular. This section is for the Toyota 4 cylinder goint to a GM V8, V6 or Buick V6.

To select the correct adapters necessary to complete your conversion, you should first identify your drivetrain. Since there are different bolt patterns found on Toyota transmissions, there will be some stock transmissions we do not offer adapters for. We have listed the stock transmission codes to aid in the identification process. These transmission codes are normally found in the engine compartment on vehicles 1979 to 1983, or on the driver’s side door jam on 1984 & newer vehicles.

The bellhousings we manufacture adapt the Toyota 5 speed to the popular Chevy V6 & V8, and Buick V6 engines. The transmissions we do not offer any bellhousing adapters for are the 4 & 5 speed transmissions (1979-83), with tranny codes L43, L45, L50, and L52. The L43 & L45 4 speeds were only used for a short time and not strong or popular enough to warrant an adapter. The L50 & L52 5 speeds were an integral (one piece) bellhousing and transmission, which makes it very difficult to adapt to.


MANUAL 5 SPEEDS (1979-1983):
In order to adapt your 5 speed transmission to the Buick or Chevy engine, your 5 speed transmission must have been originally equipped with a removable bellhousing. Between 1979 & 1983, Toyota used various models of 5 speed transmissions. These early 5 speeds are considered very weak transmissions and are not compatible for use with a new engine conversion installation. The best solution on these vehicles is to convert to either a GM or Ford automatic or manual transmission. If you prefer to keep a Toyota 5 speed, then you could obtain a transmission from a later model Toyota truck. When Toyota introduced their fuel injected trucks in 1984, they increased the strength of the 5 speed. If you have access to one of these later model 5 speed transmissions with the removable bellhousing, then you could interchange to one of these later model transmissions. You will, however, have driveshaft modifications. If you decide to use a later model 5 speed, be aware that vehicles equipped with the turbocharged 4 cylinder or 3.0L V6 engine were equipped with either a different transfer case or spline count.


MANUAL 5 SPEEDS (1984-1995):
These transmissions can be identified by transmission codes G52, G54, W56 & G58. These transmissions were normally coupled to a Toyota 4 cylinder engine. They all have the same bolt pattern, input spline, and input shaft length. These 5 speeds hold up very well to the V6 engines, but can be marginal for V8 installations. The overall assembly length of the stock transmission and bellhousing is 25-3/8". Applications retaining these 5 speeds normally will not require driveline modifications.

We manufacture a new 360 degree aluminum bellhousing that bolts directly to a Chevy or Buick engine block and accepts the original Toyota 5 speed transmission, 712560. This bellhousing is designed to work with a 10-1/2” flywheel & clutch assembly. A standard Chevy starter for the 10-1/2” flywheel will work in this bellhousing. If your engine of choice only had a 168 tooth flywheel option, our bellhousing will fit the larger diameter flywheel; however, you must use a hi-torque starter that does not have a nose cone. Engine blocks that may require the use of the 168 tooth flywheel are the late model 4.3 V6s. We offer a new hi-torque starter for these engines. 22-0001 fits both the 4.3 V6 and Chevy V8 blocks.

These Toyota 5 speeds use a dowel pin alignment when connecting to a bellhousing. When installing one of our conversion bellhouings, it is imperative that the two dowel pins be retained on the 5 speed for properly indexing. Your 5 speed transmission will retain the stock input shaft bearing retainer. This retainer provides the collar for the release bearing. The diameter of this retainer is identical to a Chevy, thus allowing you to use a stock Chevy release bearing.

Each bellhousing kit is furnished complete with a dust cover, custom pilot bushing, modified release arm, ball pivot, and necessary hardware. This kit does not include a clutch disc, slave cylinder, release bearing, and pressure plate. The items must all be purchased separately. The Toyota input shaft has a 1-1/8"-21 spline, requiring a special clutch disc. Centerforce Clutches manufactures for us a special 10-1/2” clutch disc with a 1-1/8”-21 spline, 716105. This disc will work on a stock 10-1/2” 153 and 168 tooth Chevy flywheel or a 10-1/2” 160 tooth Buick flywheel. This bellhousing was also designed to work with the Centerforce high diaphragm pressure plate, CF360056 (10-1/2”) or CF165552 (11”). These pressure plates provide ample clearance in our bellhousing and work well with the Toyota Land Cruiser slave cylinder used in this conversion. The clutch release mechanism is designed to use a Toyota Land Cruiser slave cylinder. This slave cylinder bolts directly to the side of our bellhousing and connects to a modified GM cast iron release arm. We carry this Land Cruiser slave cylinder under 716213. When purchasing the Centerforce clutch components, you will also be required to purchase a flat-face release bearing, N1430.


CLUTCH COMPONENTS:
The bellhousing listed above are designed for a 10-1/2”, 153 tooth clutch and flywheel assembly. Since some of the later model GM blocks only have a 168 tooth flywheel option, we also provide our bellhousings with clearance to accept a 168 tooth flywheel and clutch components. The only requirement when using a 168TH flywheel is that a hi-torque starter with no nose cone must be used. In addition, The bellhousing kits are slightly different. The bellhousing kits should have a “V” added to the kits listed above. 712560V .

Centerforce Clutch Components: In order to use the hydraulic clutch control mechanisms, you must make sure that your clutch is a high diaphragm design. The recommended clutch size is 10-1/2" for both the Chevy and Buick installations. The Centerforce clutches and flywheels listed below are the recommended components when using our bellhousings. We design our adapter kits around the Centerforce clutch design. If clutch components from other manufacturers are used, we cannot guarantee proper clutch operation.

For transmission conversions that are retaining the original 5 speed, it is recommended that you use a 10-1/2" clutch with a 153 tooth flywheel. Some later model Chevy blocks only came with a 168 tooth flywheel option. Our bellhousing can be used with this larger flywheel; however, a hi-torque starter without a nose cone is required. On Buick V6 conversions, the flywheel will be 10-1/2” 160 tooth. For conversions using a new transmission, you will be able to use either size flywheels.  

Clutch assembly:

CF360056 - 10-1/2” High profile pressure plate
CF165552 - 11” High profile pressure plate
716105 - 10-1/2” 1-1/8” 21 spline clutch disc
N1430 - Flat-face throw out bearing
716231 - Clutch alignment tool 1-1/8” 21 spline

Flywheels:

CF700100 - 153 tooth GM flywheel (up to 1985 blocks)
CF700170 - 153 tooth GM flywheel (1986 & up blocks)
CF700120 - 168 tooth GM flywheel (up to 1985 blocks)
CF700160 - 168 tooth GM flywheel (1986 & up blocks)
CF700010 - 160 tooth Buick flywheel ( flywheel should be balanced to crank.)

Starters: 

22-0001 - Hi torque starter (no nose cone) Chevy V6 & V8s

22-0003 - Hi torque starter (no nose cone) 153T flywheels

Slave Cylinder: We have designed our new bellhousing assembly around the exclusive use of a Toyota Land Cruiser slave cylinder assembly. This slave cylinder, 716213, is not furnished with the adapter bellhousing and can either be purchased separately from us or from your Toyota dealership under Part No. 31470-60022. This slave cylinder will bolt directly onto the new bellhousing. The stock Toyota Land Cruiser push rod cannot be used; however, our bellhousing kits come with a new adjustable push rod for the slave cylinder. The fitting size on the Land Cruiser slave cylinder will interchange directly with the original Toyota master cylinder clutch line.

Note: The stock Toyota master cylinder has a cylinder bore of .625”. The stock Toyota slave cylinder, which couples to the master cylinder, has a cylinder bore of .8125”. The new Land Cruiser slave cylinder has a cylinder bore of .750”. This new Land Cruiser slave cylinder will actually obtain more throw than the stock Toyota slave cylinder.

716213 - External Slave Cylinder (Toyota No. 31470-60022)


Driveshafts: Whenever possible, we have designed our bellhousings and transmission-to-transfer case adapters using a length that is compatible with the existing transfer case location. By leaving the transfer case in the original location, driveline modifications can be eliminated. On vehicles using the original 5 speed transmission replacing the stock 4 cylinder (carbureted or EFI), driveshaft modifications can usually be avoided. Vehicles replacing the stock V6 and retaining the 5 speed will require driveshaft modifications. Vehicles replacing the turbocharged 4 cylinders may or may not need driveshaft modifications.