Transmission Center


Buick Straight 8 Transmission Adapter kit Installation Instructions



The kit shown fits 233/248/263 Straight 8 motors. 320 motors are slightly different, but the assembly is similar.


All parts (even the flame cut plates) are CNC machined and ground. They are all steel and they always will be. I like the rigidity of steel. The

weight is negligible


We assume that the person installing this kit has a certain amount of mechanical aptitude and ability. It is not for the beginner. Make sure you clean all surfaces when mating these parts together. Always check bolt clearances. We try to make everything as simple as possible to help you, but the ultimate responsibility as to the assembly of the kit is up to the installer. Check and recheck as you go. We canít foresee every change or modification that could possibly occur in the building of a custom vehicle. Especially when we are dealing with 50-year-old motors.


A few common sense installation tips.

1.      Install all bolts before tightening in any sequence.

2.      Use loctite and torque bolts where applicable.


Most of the kit has been assembled so you can see how it goes together.


The kit contains the following:

 1. Two adapter plates, an inner and an outer.  

 2. Crank spacer.

 3. Mini high torque starter       

 4. Flywheel.

 5. Bolt kit



With your transmission removed, clean the back of the block where the adapter will contact it. Make sure both alignment dowels are in place.


Bolt the inner adapter plate to the block with the 2 tapered-head cap screws and the 4-2 inch x 7/16 bolts provided. The 4-2inch  bolts go through the block, into the adapter plate. On some blocks, one of the bolts needs to be ground shorter. Watch and make sure the bolts donít stick out through the adapter plate. If it does, it will interfere with the second plate. After this is done, install the crank adapter using the provided bolts. There are several different styles of crankshafts used on the Buick straight 8 engines over the years. We have crank adapters and bolts available for all of them. If your engine originally had a Dynaflow transmission, your crank flange should be threaded with 7/16 bolts.. If you had a manual transmission, your crank flange should have threaded inserts with 3/8 bolts. Make sure the crank flange is clean and no burrs before installing. Use loctite and torque to specs evenly. Now install the spacer plate. It will slide onto the extended dowel pins, pressed into the adapter plate.  It should be a tight fit. Tap it on without damaging it. Next the flywheel. You should now be ready to install any Chev V8 style automatic transmission. If you want to install a manual transmission, you simply bolt on a 1985 or older Chev stick flywheel and clutch assembly, along with the Chev bellhousing.


If using a manual transmission, drive the pilot bearing adapter into the crank spacer AFTER the crank spacer has been installed. Part of the pilot bearing adapter drives into the original crank shaft, so make sure that it has been bottomed out fully. Then use a stock Chevrolet pilot bearing or bushing.


 Caution! We have found several motors that have had the crank flange & bolts modified to take other types of flywheels over the years. When ordering, you will be asked what bolt system you crank flange has. 


    Bendtsenís Transmission Center Inc.  763 767 4480

        13603 Johnson St NE,Ham Lake, MN. 55304



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