nuh-uh bro,if u check in the tech section,there are specs for all 3 of these engines.there is no way in hell that the a12 and a15 have the same power.it doesn't make sense.
a12-69hp
a14-78hp
a15-81hp
go 2 the section and click on engines.u will see a10,a12,a12a,and a14 and a15.click on a12 and a14 and a15...u'll c

horsepower-wise the 1500 is more powerful than a 1400 and both engines will fit in your sunny with very,very,very little or no modification.remember that sunnys came with the 1200(a12) as well as 1400(a14) and 1500(a15),so the engines will fit as factory. my sunny has a 1500 out of a vanette.fit in without any modification at all.the only thing is that the 1500 exhaust is thicker than the 1200 so i have 2 change in exhaust system.but it runs fine with the 1200 exhaust.generally 2 me both the 1400 and 1500 are great.both put out a fair amt. of horsepower and torque and are very strong engines.the extractors should be able 2 bolt up to the 1400/1500 engine without trouble.hope that answers your question.

i also drive a b310 with a vanette a15(changed from the a12)but with automatic.i used the same a12 exhaust system so sometimes i don't get sufficient power from it as the a15 exhaust is bigger.one time i ran on the highway and reached approx. 150km/h(would have reached 160 if i hadn't come of the highway).if it's not the exhaust it probably the timing.u may need to check that out.

in the caribbean the most popular datsuns before '85 were the 1200s & 120ys(b210 & b310).they were cheap and very neat lookimg cars.they were popular in barbados and trinidad and still are.

you guys may not believe me when i tell u this but i actually saw with my own 2 eyes an L28 in a b210 120y.ofcourse he did have 2 cut the firewall etc and let me tell u that car is one of the fastest 120y i've ever seen.i wish i had some pix to show y'all.so may an l28 should fit in a sunny with some cutting and all,but thats too much trouble anyways

I agree with mawler1,if u do decide 2 put on bumpers,get the aussie/jdm spec bumpers 'cause those us spec bumpers are uuuuuuugly!!!!

Hmmmm......that would make PERFECT project sunny

I once heard that a man put a cd20 diesel engine in a b310.Its the craziest thing i've ever heard someone do 2 a b310...I mean y would someone put a diesel in a sunny?!

I saw that sunny on ebay.the owner said it has a ca16 pushing 110ps.Could do with some more horsepower don't ya think....and converted is right...that is the best sunny I've seen next to datman55's fj20turbo sunny

I saw a 720 with an rb20det once.I was told that the owner did some cutting etc,but it fit right in.So the ford straight six should fit