I'm finally getting around to building my 1972 Twin dizzy 12a. Everything internally looks great. Housings look near mint as well as the plates. All seals move freely and spring back nicely. I will spec them out before trying to reuse anything though, but I'm sure they will all be within specs.



I am going to use this on a newer 2nd gen FC tranny, so the problem is the rear plate. Can I just swap on a newer 12a rear iron? Is there any other way I should go about doing this?



I also was tossing around the idea of using the twin dizzy rotor housings and rotating assembly with all three newer 12a plates. Basically because I have someone that wants to buy my plates, and I would prefer to use plates with the nitride coating.



Any tips here would be nice!

 

I knew the twin dizzy had more bolts than all the newer motors. But it's actually only by one tension bolt. Which is fine since it's right about where I would put my PP anyways. So It would become obsolete anyways.



But one thing I wasnt ready for, two of the tension bolt holes do NOT line up properly. One just below the spark plug area, and one just below the exhaust port. If I look through, only about half of each hole is visible. So if I were to use newer 12a plates, could I just mill out the 2 holes that do not line up properly in the early 12a housings?











Here's a pic to point out the areas:





















On a side not, the twin dizzy tension bolts are much thinner also. The twin dizzy tension bolts are just under 7mm, and the 13b tension bolt I measured was around 9.4mm. The thread and pitch is the same. Obviously not as long, but none the less the same thread. So Could I use a newer set of 12a tension bolts as an upgrade on this motor?

 

yeah i'd run the newer 12A bolts. i'd also see if the 17mm oil pump bolts in too.



and run the newest stationary gears too



you also could use the newer 12a rotors, but still run the carbon seals

 

i get tripped out everytime i see those old, fat OEM carbon seals.

 

You would be impressed how light they are too!

 

i bet they are. out of curiosity, if you were to use those rotors again, where would you source the apex seals?

 

I would just re-use the ones I have right now. But If I were ever to need another set. That might be a problem. I have seen them pop up on the forums a few times, and on eBay once or twice. The thing is, someone has a set. So if you put up enough wanted ads...They will come to you.

 

Does that have dual side seals on the rotors???

 

yes it does.You can see them in the pictures I posted above.

 

stack 2! actually bumped into a guy who said he had some new ones still. i dunno, dual side seal and 5mm apex = doorstop IMO