Don't know if 100 is achieveable but as for the questions

1. I'd try the A12 head first
2. A12 flywheel will be fine on the A15. I use one.


Thats all I have

Ok this week I landed an 81 A15 powered wrecked Datsun for a whooping $60 so at that price I figured time to upgrade from the modded A12 that's pumping out 85HP

The goal is a 100HP A15 (I've been racing the A12 for 16 seasons)

So here are my questions;


My current A12 uses the so called H-production head (Kidney shaped chambers with round ports) , the head has A14 swirl polished valves with a very good port job , header and a single side draft Dell Orto. (I believe this year A15 in the USA had a smogger head.) So use the worked A12 head or work the A15 econo head?

oil pump should swap straight accross correct? (the one in the A12 has been modded)

A12 flywheel should also bolt on (car has an Auto Box) plus A12 flywheel is lighter , correct?

Finally cam spec: I wish to keep a non interferance fit motor. I instruct at a ton of track days and have been distracted with a student in the car and floated the valves once (8100RPM's) So I am thinking of using the GX spec cam.

So to sum things up I'm looking for 100 HP using an A15 with worked A12 round port head , A14 valves and dual springs , single side draft Dell Orto (LF hand drive car dual carbies foul the master cylinder) , Header ,2" exhaust, A12 Flywheel and a GX spec cam.

Thanks in advance , Tom

Note; I use a 4 speed box with an H145 LSD and the 530KG pressure plate