Specifications

CHEVY, FORD & AMC BELLHOUSINGS
There are several types and styles of bellhousings that can be used on Jeep engine conversions. The variations will limit you to
different clutch sizes, starter motor configurations, release lever options, transmission index diameters, and bolt patterns. We have
outlined some of the various available bellhousings that will be compatible with your Jeep engine conversion.
A. Chevy Bellhousings: When selecting a Chevy bellhousing for your engine conversion, you must make sure the inside
diameter of the bellhousing will be compatible with the clutch you are going to use. We recommend that you use the 11" flywheel
and clutch assembly, which will require the large inside diameter bellhousing. In order to verify that the bellhousing will fit the large
flywheel, you must make sure the inside diameter will clear the 14" diameter flywheel. These bellhousings are more common on
truck applications, but there are several car-type applications that also have the larger diameter. Once you have established the
larger inside diameter, you must then verify the transmission register diameter. GM offers two different diameters. The large diameter
is limited to late model trucks and the small diameter is usually found in Chevy passenger car applications. If a bellhousing adapter
plate is going to be used, we supply a bearing retainer on the front of the adapter plate that will index into the 4.686" diameter. If
you purchase a bellhousing that has the 5.125" diameter, then you can order our index ring P/N 716078 that has the larger diameter
for the 5.125” bellhousing index.
GM has always used the same transmission bolt pattern up until 1993 when they introduced the NV4500 5 speed transmission.
In 1996, GM bellhousings started to incorporate an internal hydraulic release bearing and, once again, they changed the
transmission bolt pattern on the bellhousing. You must be careful when selecting a NV4500 transmission to make sure that you
obtain the proper bellhousing. We offer numerous bellhousings that will fit most applications.
The engine block bolt patterns have always been the same for the Chevy small block and big block engines. The bellhousings are
aligned by two dowel pins that are normally on the engine block. Without these dowel pins, severe misalignment of the bellhousing
and transmission will occur.
On all Chevy applications, the starter motor locates on the engine block with exception of the very early 265 V8s. When using the
stock bellhousing, no special starter will be required. We recommend that you try to retain the 168 tooth flywheel for all conversions
using stock GM bellhousings.
Our conversion bellhousings are designed to work with a stock Chevy starter nose cone. We have found that some GM starter nose
cones will cause interference inside our bellhousing. If your stock starter is interfering with our bellhousing, you may need to grind
on the bellhousing a bit or purchase a hi-torque starter which does not have a nose cone. When using a 168 tooth flywheel with
our conversion bellhousing for the 1987-2005 stock Jeep transmissions, you will be required to use a hi-torque starter. We carry
a hi-torque starter for the Chevy V6 and V8 under P/N 22-0001stagered pattern, and a hi-torque starter for the Vortec blocks under
P/N 22-0002 and a hi-torque starter for the straight bolt pattern under P/N 22-0003.
B. Ford Bellhousings: When selecting a Ford bellhousing for your engine conversion, you must make sure the bellhousing
you select is compatible with your engine flywheel. On Ford bellhousings, the starter motor has a predetermined location that can
only be used with either the 157 tooth or 164 tooth flywheel. On some V8 engines such as the Windsor, a 157 tooth flywheel is not
available. Problems can be avoided by selecting the proper bellhousing. Once you have established the correct bellhousing
diameter for your flywheel, you must then verify the transmission register diameter. Ford offers three different diameters. The small
diameter of 4.848" is common to all car and some truck applications, while the 5.125" diameter is limited to early trucks. The 4.910"
is used with the T4 and T5 transmissions. If a bellhousing adapter is going to be used, we supply a bearing retainer on the front
of the adapter plate that must index into the 4.848" diameter. DO NOT ATTEMPT to use the Ford bellhousing that has the larger 5.125"
or 4.910" diameter.
The bolt pattern for the transmission will always be the same on Ford bellhousings 1966 and newer. The early bellhousings (up
to 1965) have a different transmission bolt pattern and are held to the engine block with only 5 bolts. All of the adapters manufactured
are only compatible with the late model bellhousings. In most cases, the bellhousings will already have a clutch release lever, ball
pivot or mounting bracket.
The bellhousings are aligned by two special dowel pins that are normally on the engine block. Without these dowel pins, severe
misalignment of the bellhousing and transmission will occur. Since the starter motor locates into the bellhousing, you must make
sure that the starter, flywheel, and bellhousing are all compatible.
C. AMC Bellhousings: Some applications will require the use of an AMC bellhousing. Listed below are the AMC blocks that
share the same engine block bolt pattern. AMC bellhousings are similar to the Ford bellhousings in that the starter bolts directly
to the bellhousing. We have found that Jeep used two different starters. The bolt pattern on these starters are the same; however,
the amount of engagement of the Bendix is different. Make sure that the starter you are using obtains proper engagement with
reference to the Bendix and flywheel.
(Note: AMC includes 258, 304, 360, 401, 4.2L, 4.0L all of which have the same block bolt pattern.)
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chevy, ford & amc bellhousings