Early Hemi Parts

Wilcap Co.


Other Parts


806H S. Division St. Waunakee, WI 53597 (608) 509-1113


Jim Benitez/Jalopy Shoppe RPU




Thank you for your inquiry about our engine to transmission adapters for Early Hemi and Poly engines. We currently have several types in production for these engines. We've been making Early Hemi adapters longer than anyone else in the business and there are more "Wilcap" adapters behind Early Hemis than any other brand

Part Number Guide

Engines I.D.
331=1951-1953 Chrysler (331 C.I.)
BH = Bellhousing
392=1954 - 1959 Chrysler, 1953-1959 Dodge 1952-1959 Desoto. Includes Poly motors.
AT=Automatic Transmissions
MT=Manual Transmissions
FE= Steel Billet Flywheel
AL = Aluminum Billet Flywheel with Steel Friction Face
350= Chevrolet Small and Big Block Bellhousing Bolt Pattern
318= Mopar Small Block Bellhousing Bolt Pattern
302= Ford 1965 up Ford Small Block Bellhousing Bolt Pattern
BOP=Buick Olds Pontiac Cadillac (1966 to 1986 Iron Block V8) Bellhousing Bolt Pattern
FTL= Ford 1965-1978 Transmission Bolt Pattern
FT5= Ford 1979-1992 Borg Warner T5 Transmission Bolt Pattern
For more detailsgo to our "Downloads" page and find the part number by Engine C.I. to download our Product Sheet and Instructions

P/N 392-350AT is for late General Motors automatics (i.e., Powerglides, Turbo Hydramatics, THM 700-R4, etc.) or 392-350MT is for any manual transmission using a Chevrolet bellhousing originally designed for the iron block engines. It comes drilled with the Chevrolet Bell housing bolt pattern. It can be ordered with the BOP bolt pattern to bolt directly to late Buick, Olds and Pontiac transmissions/bellhousings. This adapter kit contains the adapter plate, a crank hub spacer and a flex plate. The adapter is 3/4 inch thick and also uses the late model Chrysler V8 starter, mounted on the left or by request on the right.

392-350AT- Early Hemi to Chevy Automatic

Available with starter on either side and with or without Buick/Olds/Pontiac bolt pattern (392-350ATBOP = Auto adapter with BOP pattern) Download PDF (Product Sheet Download)


392-350MT- Early Hemi to Chevy Manual Transmission

Available with starter on either side and with or without Buick/Olds/Pontiac bolt pattern. Available with billet steel or aluminum flywheel Download PDF (Product Sheet Download)


392-318AT- Early Hemi to Chrysler small block auto transmission Download PDF (Product Sheet Download)

For the Chrysler A 727 Torqueflite (i.e., 318, 340, 360 bell housing pattern). It consists of an adapter plate, a crankshaft hub spacer and a flex plate or flywheel. This adapter is 1 inch thick and uses the late model Chrysler V8 starter that bolts to the transmission in the stock location. We have been manufacturing this one since the mid sixties.



Manual Transmission version for A-833 with Small Block bellhousing. Availble with steel or aluminum flywheel.

392-318MT- Early Hemi to Chrysler small block manual transmission Download PDF (Product Sheet Download)


392-302MT- Early Hemi to Ford Small Block. Download PDF (Product Sheet Download)


The 331-318AT adapts the 1951-1953 331 Chrysler ( Extended Block or Bellhousing) to Chrysler 727 automatic. You can download the product sheet here:Download PDF

This adapter uses a modified small block Chrysler transmission case. No modification of the block is needed. The three choices for installation are: Send us your transmission (assembled or case and front pump only), send us your transmission front pump, or we'll send you the adapter only. Adapter includes complete instructions for modification of your transmission and for alignment of the adapter to your transmission, flexplate, hub spacer, and fasteners. Includes flexplate. Uses stock or aftermarket starter.

Installing a 331-318AT into a Chrysler Imperial


The BH 331-350 adapts the 1951-1953 331 Chrysler ( Extended Block) to the Chevy "Muncie" transmission bolt pattern and is designed to use your stock 331 flywheel and starter and a hydraulic throw-out bearing. Comes complete with fasteners, instructions, and pilot bearing adapter. Download PDF


BH 331-FTL - 1951-1953 331 Chrysler ( Extended Block or Bellhousing) to Ford "Top Loader" 1964-1978. Uses Stock flywheel.Uses stock or aftermarket starter.Download PDF


331-FT5 - 1951-1953 331 Chrysler ( Extended Block or Bellhousing) to Ford T5 1979-1992. Uses Stock flywheel. Uses stock or aftermarket starter.Download PDF



392-EFM- Early Hemi to Early (1932-1948) Ford 3 & 4 Speed Transmissions.Download PDF (Product Sheet Download)

P/N 392-EFM Adapts the Early Hemi to the Ford 1932-1948 or Merc 1939-1950, Ford Truck 1/2 to 1 1/2 ton 1949-1953 transmission. The adapter moves the starter to the passenger side. The original starter plate is required (#1613713 or equivalent). Includes the pilot bearing adapter and fasteners. We can supply the correct pressure plate and clutch disk for this adapter.




Keep the oil flowing and the oil filter out of the way. Includes gasket, fasteners, and instructions. Download PDF



REMOTE oil filter adapter.

Tapped for 1/2 NPT threads. Gasket, instructions and bolts included.





Critical little part! Forces all of the oil through the filter instead of allowing a significant portion to bypass the filter. Replaces the original bypass valve located under the rear main cap.



Wilcap makes 9 different versions of the Early Hemi Flywheel;

 Part Number

 Description / Material

 Ring Gear

 Avail. Pressure Plate

 FW331M  Marine flywheel  Aluminum  146T None
 FW331AL  Aluminum  With Steel Insert  146T  4,5,6,7
 FW331S  Replacement Steel  146T  4,5,6,7
 FW392M  Marine flywheel  Aluminum  172T  None
 FW392AL  Aluminum  With Steel Insert   172T   4,5,6,7
 FW392S  Replacement Steel  172T  4,5,6,7
 FW392350M  Marine Aluminum for use w/adapter  130T  None
 FW392350AL  Aluminum W/Steel Insert for use w/adapter  130T  4,5,6,7
 FW392350FE  Steel for use with adapter  130T  4,5,6,7


Pressure Plate Bolt Patterns;

 1.  8" Diaphragm
 2.  8.5" Diaphragm
 3.  9 1/8", 9 1/4", 9.5" B&B and Diaphragm
 4. 10", 10.5", 10.95" B&B and Diaphragm
 5. 11", 12" B&B and Diaphragm
 6. 10", 10.5" Long and 10" B&B and Diaphragm
 7. 11" Long and Diaphragm
 8. 11.5" & 12" Long and Diaphragm





Chrysler used a common block and crank shaft pattern on the Dodge, Desoto and Chrysler Polys and Hemis EXCEPT for the 1951 to 1953 331c.i. Chrysler, also called an extended block.

1951-1953 Chrysler Extended Block

The extended block has a round pattern that is similar to an S.A.E. pattern found on industrial engines and uses a cast starter housing that bolts vertically to the engine. One word of advise; don't lose the starter housing as it can be tough to find.

The rest of the Hemis use a bolt pattern that is common to the Chrysler LA Small Block and the new 5.7L Hemi BUT the dowel pins are in different locations and the crankshaft stickout distance is different. And while you can bolt a LA bellhousing up to the early Hemi, there's a lot of grief involved in getting it right and even more if you don't.


Also the 426 Hemi flywheel has the correct bolt pattern but does not register on the flywheel correctly and can't be used.

The crankshafts all share a common 8 bolt pattern and all use the outside diameter of the flange to register the flywheel. One bolt hole is offset. They all used 7/16" fasteners to attach the flywheel and stock they are not threaded.

All of our Hemi adapters come with the option of 1/2" crank bolts. The holes are drilled to a few thousands over the tap drill size for 1/2-20 NF. If your going to install a manual trans its worth the time to tap the holes. We can supply a "loaner" tapping fixture to our customers that makes the process easier.

There are multiple sizes of pilot bearing bores and it is best to measure bore before ordering a manual transmission adapter.


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Wilcap Company

806H S. Division St. Waunakee, WI 53597

(608) 509-1113

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