Apart from the cost of the engine ($200ish up) I think if you did the swap yourself it could cost bugger all really, maybe $10.
Stock radiator will be fine , standard ute diff will take all the punishment your A14 will ever be able to give it.

You may need to swap the alternator from one side to the other and get a bit of angle to modify the mounts, but its not anything that would cost any money really.

Cabridge,I am sure you did see correctly , there are pics on this site of setups like that.(two motorbike carbs)
It is the same concept as twin SUs.They can work great.
I had twin Hitachis on an A15 for years and they never needed the slightest adjusting.
I also had quad bike carbs on the A15 for about two years.
But for all out power I went for twin webers.
If I had the money I would get four HSRs in a flash.

I would say the bike carbs any day for driveability, but for 4 Mikuni HSRs you will be paying over $2000 aussie.
If you could find something else with a 40mm+ bore to get the top end(remembering our datsun engines are generally bigger than most bikes you would be getting the carbs off) I would think you would be onto a good thing.

I got the diff and steering column for my KB10.

All the boxes that fit A12s fit A15s.

Sounds promising.

One is for the front brakes one is for the rear.
The clutch is activated by a cable.
I think you need to find some brighter revhead mates as this is very basic stuff.

Twin carbs and extractors will help it breath better.
I had good performance from factory GX twin Hitachis, keep an eye on Ebay.

Coops its unfortunate that you lost your money,but dont take take all this revenge talk to heart.
Use your time and energies on bettering your own life, forget about that jerk,dont lower yourself to his level.
Take it as a lesson and move on.
Dont fall into the trap of carrying grudges and wasting time and energy on something that ultimately will do nobody any good.

The flares I had are gone ,but for any interested parties here is Steve Drahiems Email address, he is still making these fibreglass parts, and if your building a track car they are just the ticket.

sdrahiem@ozemail.com.au