I just picked up the first truck load of old Mazda driveline parts. I have some questions for you:
What do you know about a 13B with a 3B Block?
How can you tell the difference between Rx2 and Rx3 trannys?
How much differnce between the short and long RB headers (two pipes down to a flange).

 

Old rx2 trannies have the top mount starters. I could be wrong on this but I think the rx3 had bottom mount only.

 

I think the 12A Rx3's have topmonted starter as well.

What's a 3B 13B block?

//magnus

 

Mazda went to bottom-mount starters in 74, across the board. Anything pre-74 is top-mount, anything 74-up is bottom.

 

The 3B 13-B block is what came in the REPU

Dan

 

Yes, and there is no dash or hyphen between 3 and B.

 

Ok, another question, which has larger ports a 3B or 5H (I think it is an H)?

 

3B had the largest ports of any pre'86 engine. A typical street port is larger of course. 3B exhaust ports were small.

 

Thanks Jeff!