hey all i see some twin dizzy pp housings in engines pop up every now and again that just looks like they have opened up the exhaust ports as far as poss, if you were to spend the money on getting the housings pp sleved surely you wouldnt use twin dizz housings? i used a set in my 12a and they dont make the sort of power any other single dizzy housings will make , so ive been told they wont make serious power because the exhaust port is just a bit low, any twin dizz guru's out there?

 

The rotor housings that came in the twin distributor front cover were a bit on the lame side but could perform as well

as more modern housings with a bit of work.



The front covers are interchangeable through many years. The irons are not. Also the early irons are smaller at the bell housing face and later transmissions will not bolt up.



You can build up a modern engine with an early rear iron, and then use the early transmission and bell housing. You need the smaller diameter flex plate or flywheel as well. The early stuff is all top starter and it takes up lots of room. Plug the unused case bolt holes lest the water run out.



There is no parts support for early or late 12 A stuff now. You can mix and match irons from 13Bs but you may be building

extra material onto the intake to match up the port runners. If you use irons with grooves you can manufacture 12A rotor housings on a mill. Just slim down a set of good 13B housings. Even those with chrome flaking at the edges will work as you clean that off.



Lynn E. Hanover