Broke a rod bearing in our '72,1200 which we have owned for 33 yrs. Rather than rebuild want to swap. What would be the simplest swap but also provide the most power for Southern Ca. freeway driving? Found a '69, 1600 roadster but also looking at an A14. Heard the roadster engines are junk? Suggestions? We have an AT in it that has never given any problems. Keep it?>

Thanks

Go with the A14. Simple modification of motor mounts, the exhaust flange on the header and route your alternator wires to the other side. If electronic distributor than wiring for that. That should be about it.
Other can add if there's more.

Thanks.

Another question I might as well is, I've heard the rear end on a 1200 can take the torques of a 14. If that's true, do I need to get a different rear end and if so which one? Also, is there much fabricating in going from a AT to a 4 speed? Thanks for your input.

Roger

If you go from a 1200 AT to a 1200 4 speed you may have issues with the mounts and drive shaft.
If you go with an A14 tranny you will have to build tranny mounts and get a A14 drive shaft. If you stay with the AT, you should be fine. 1200 rear diff is fine for a A14.

What I would do is keep the AT, get an A14, and swap in a higher final drive center section "pumpkin".

Although 3.7 accelerates slower than the 1200's 3.9, it will reduce the RPMs on the freeway. The good news is that the higher torque of the A14 will pull a 3.7 gear ratio no problem. (If you keep the same final drive, you have the same RPM issues you have had before). Also have an external AT oil cooler fitted as the 1200 transmission is aircooled and will need a little extra cooling with the big motor and high speeds.

A14 is a direct bolt in for an A12A. If replacing an original A12 some simple motor mount bracket adapters are needed. If you currently have a 2-bolt exhaust pipe a swap is needed for the A14 3-bolt type. Any exhaust shop can modify the end of the pipe.

Automatic trans means bigger tunnel.

I would go L series if I were you. More clearance for the transmission. It is something I have always want to do to one of my 1200s

Thanks for all the suggestions.

We purchased that nice A14 in Bakersfield you mentioned was available. It has a 4 spd but we are going to keep the AT for now. Thanks.

Question: Do we need a larger radiator for the 14 instead of the one for the A12A we removed?

1200 radiator is OK if in good shape. They tend to run warm though.

Just add aftermarket transmission cooler if you dont already have one. Or fit a new $125 Datsun 210 radiator from Oreillys. It has cooler lines in it. That one was designed to cool A14 and is just a bit wider than stock 1200 unit.


How did your 1200 end up with an A12A engine instead of the stock engine?

Sorry for taking so long in responding to your previous inquiry about how our 1200 had a A12A engine I replaced with the current A14.

I purchased it a number of years ago from a engine parts shop thinking it would just fit on and into the motor mounts and etc. Was I surprised.