lots of good advice already here.

A few things to add.

First bring money. Most issues can be solved using cash.

Yoshifab has adapter plates for motor mounts to adapt the b21-b230 to the early mount brackets.

Easiest solution to the trans is a Dee Works T5 adapter (Works upright or slanted) that gives you a real 5 speed. Call it $1500 or so.

Inclined VS up and down: Big issue for me is the intake manifold/brake booster clearance. Not good inclined and worse up and down. $??.

Induction issues follow the above. MSEFI is likely the easiest approach. Webers open up brake booster clearance issues when inclined and are worse yet, mounted upright. For all the trouble here going to a 16v really starts to make sense. Good manifolds are available for 16 V (at least for Turbo charged apps, but N/A is an unknown as far as fuel distribution N/A). Issue being the inclined motor intake angles down in the normal install and in the "up and down" install it is even lower and clearance to booster and even steering really gets dicey.

Were it me, I would listen to B20Paul and go with a B20... Bore it, mebe stroke it, upgrade an F head, add MSEFI and crank triggered ignition (HIF-6s are just fine too). Use a somewthing like a D cam or even a KG10 if you can get one. Don't monkee around with headers, the stock 4-2-1 exhaust is fine for anything you might need as a street car. Add a Simons 2" sport exhaust or even a 2.5" (the 2.5 may actually have diminishing returns, performance wise... I would go with 2.25" if you have a good exhaust man. No reason you cant get 135 rwhp out of this... stock was surely less than 100 RWHP.

Always do a proper, well balanced set of mods to the the engine, focusing on breathing and quality parts/assembly. Certainly nothing wrong with lightening the rotating assembly using modern rods and pistons. As much as 4 lbs can be lopped of the rotating assembly with just rods and pistons (call it 900 bucks or so here) and that ain't chicken feed.

So that is my input. I've done swaps before and they can be a real snake pit. That is the logic I used in my project, It wasn't all mine. most of the same folks posting in this thread have contributed to my plans and current Amazon project.

If ya wanna get a little wild, Paul has some interesting thoughts on a stroker approach for the B20.

Just depends on what you wanna do, I guess. New limits except lack of cash!!!

mike