A 20b is 5kaud second hand if you can find one and blow a seal and your rat.shit
for a 2.5k aud housing. A lexus v8 is ten times the engine a 13b is, weighs less,
dirt cheap and then dont get me started on 2jz an engine where top rotaries racers
are moving to for price and performance.
You cant beat pistons period, the rotary is like a fuse, short lived, bright
for a short time and very expensive now.
Also most datsuns with mazda engines are not worth silch compared to nissan upgrades.
Pistons are here to stay until a real rotary solution arrives = AC electric motors.

Most datsun lovers like going around corners rather than a few second in a straight line.