Coil placement for 42-48 Flathead

[Jordan Baker]

Even if you change over the front plate, the 42-48 flatheads have the cam head sitting back a bit more then the 37-41 flatheads. Although I have seen a small adaptor spacer you can buy and it then allows you to have the diversbell distributor instead.

[Tony Smith]

Originally Posted by Jordan Baker

Even if you change over the front plate, the 42-48 flatheads have the cam head sitting back a bit more then the 37-41 flatheads. Although I have seen a small adaptor spacer you can buy and it then allows you to have the diversbell distributor instead.

Other way around. The 42-48 cam is LONGER, the 37-41 cam is SHORTER.
If you want to put a 42-48 "Crab" distributor on a 37-41 engine (221ci), besides swapping the front cover plate, you need ONE OF THESE. If you want to put a 37-41 "Diver's Helmet" distributor on a 42-48 engine, you need ONE OF THESE.

If you want to keep a Diver's Helmet distributor, but want to move the coil away from the front of the engine (or convert to 12v), you want ONE OF THESE

Virtually all of the electronic distributors require converting to a 12v system.