counter weight question
 

13bt into a 1985, iam using the 12a tranny, i switched the fly wheel now i have the use the counter weight for the 12a flywheel when installing the weight? is it put on in any position? or could be put on anyway just as long as its the same weight so question is proper aliment for counter weight? thanks and has anyone used a 12a tranny with a 13bt engine how long would it last? normal driving (ie no banging gears) because normal driving is at 6-7k =)

also.. what fuel pump would be best to use for this setup besides dropping in the turboII pump in the 12a tank?

you have to use the counterweight based on the rotors in the engine. that is what the weight is balancing out. S5 rotors, S5 counterweight. S4 rotors, S4 counterweight, etc...

as for the position, the weights are keyed. there's a notch in the center hole.

so what is needed when switching the flywheel? or are they all insync? front blance with same rotors same flywheel?? thanks for help

Leave the front weight that is on it alone, no need to touch that. I don't know, but would think that the original flywheel would not work for your application, either the T2 one or the 12a one. T2 fw probably wouldn't line up with the 12a tranny and starter (it would be larger diameter), and the 12a Flywheel wouldn't be balanced for the new rotors (if it's like FC's, the original Flywheel has the balancer weight built into it which would not be correct for the new engine). If you could use a T2 tranny, then using the original flywheel would be no problem. If not, you'd probably have to find an aftermarket flywheel and use the rear counterweight that would match the rotors. Call up racing beat or mazdatrix and ask them your questions, they can tell you for sure what you'd need.

As for the fuel pump, well T2 fuel pumps are 15 years old. Since you are going to have to replace the 12a pump anyway, you might as well get a new walbro or the like.

edit: oh and if you haven't already, post in the first gen forum, i'm sure there are more guys there who have done this swap than are here.