i have both engines, 12a/13b/ my question is:

i want to take the 12a racing beat exhuast (with out the exhuast monifold on the 12a) put that on my 13b with the stock monifold.

they seem to line up under the car the same way, but i dont know the dimension because i just got this idea and im at work. i did search

 

im thinkin that would be a no go?.. lol

 

Your statement is hard to follow.

If you are stating that you had a racing beat exhaust system on your 12a, then it would of been with the header.

If you are trying to attach the presilencer to the 13b stock exhaust manifold it is not a bolt on. You would have to fabricate from the end of the stock 13b exhaust manifold to connect to the presilencer.

But if you had a complete 12a exhaust system including the header. You could split the header in the center where it bolts to the engine and cut and lengthen the header tubes to match.

But then again, I'm not quite sure what you have.