I have found that most things that look simple are very complex, and most things that look very complex, are not really well thought out. Complexity always seemed like after thought to me, simple clean lines, show thought and care from the engineers.
The material this coupler s made of is 4310 steel, its heat treatable if desired, but I assure you , its not needed

I like to take great care in my demensions, i wanted to create the back of the original M/T flywheel for my coupler, to make absolutly certian on my centers

The holes are all drilled witha CNC bridgeport, first in metric for the Mitsubishi crankshaft and then in standard for the GM flywheel

I cut off a Mitsubishi crankshaft end just to allow testing in my lathe, I chuck it in exactly square before testing

with flywheel installed , the whole system is spun at top speed, the flywheel must spin true


all my adaptors come with the bolt pattern for the narrow block/wide block and second gen 4G63 engine blocks included

I used a toyota truck starter just because they are cheap, they are a generic reduction starter used on everything, all that is needed is a $15.00 pinion gear from jegs to use this starter

the starter fit is excellent, this is an OEM intake manifold for the 4G63

the adaptor mounting bolts are slightly reccesed because my adaptor plates are 3/4 not 1/2 plates, I needed the extra space to allow the upper apron for the bellhousing and I added an extra 3 mm in the bolt lands of the coupler to increase the horsepower the coupler could withstand