i think you can go past a rotary. ive had 2 13bt powered 1200 utes. one i still own and one i sold. both wild as hell cars to drive. the first one i had was a standard series 4 13bt with no mods. car ran a 12.2 @118 mph quater. if i had traction i have the mph to run an 11.3. car had heaps more in it. just struggled with wheelspin.

ive driven a mates ca18det ute. my mate has had more trouble with it then any rota i have ever owned. blown head gaskets. etc

if you drive a rotary properly with good oil and good fuel supply you wont have any problems with it. unless you over rev it and dont warm it up.

with both engine packages there is enough power to beat most cars on the street and they are both fun to drive.

the issue i had with the ca18 is the shifter sits to far back in the car as to the 13b it sat forward and was easier to drive.

the rotary made power strait away as the ca was power at the top. maybe different in other cars.

even if you put a 12a in the car with porting it would still make good power. just as much as a 13bt if the right guy built it.

another plue with the rotary is that its heaps lighter and heaps more room under the hood.

each to their own i guess. hope this helps out