As far as I know there is no V8 that will bolt up to the Fiero trans. FWD GM 4 cylinder (not including the Quad 4 and variants) and 6 cylinders (not including the 4.3 derived from a 350 block) will bolt up. This "limits" your bolt up choices to displacements of:
4 cyl: 2.0?, 2.2?, and 2.5
6 cyl: 2.8 (FWD),
3.1,
3.4,
3.4 TDC,
3.8 (FWD or current F-body RWD)
I say limits because you have from 90 hp to 240 hp stock in that list (supercharged series II 3800).
To adapt a SBC V8, you will need an adaptor plate, specific clutch/flywheel, etc. I strongly encourge you to look into the Zumalt V8 kit ($1800). Everyone raves about the quality.
Another alternative is to transplant an entire FWD V8/tranny combination (aka Northstar) but this would leave you with an Automatic, a choice that may not fit with your driving style.
From: David Cole
Engine swaps take time, money, cunning, tools, and the ability to engineer (tinker),-- and patience! It's supposed to be fun. When it ceases to be, then it's time to back away and do something else and give it a rest. It ain't no week-end project. The time you allot to this will be nowhere near the actual time you'll spend on it.
If you want to upgrade your 4 cyl., yes, the easiest AND CHEAPEST way is to sell your beloved car and buy a 6 cyl Fiero.
So why am I doing this? No, I'm not crazy, but it looked like a doable challenge and would be fun. The fun part is beginning to get thin.
As for money, Mr. Cheapy ain't going to spend any more than is necessary. I'm fortunate in being able to do all the work myself, so I've got under a $1000 into this project. No financial records are being kept (except rough mental notes) for fear of raised eyebrows from the better half ;).
From: Tin Man
My 'attitude' is not against swaps, just against taking them lightly; If my attempts to discourage succeed, then you may be better off, and money ahead; If they don't then I hope I've enlightened you to the complexities involved; I take the same stand with fiero rebody 'kits';
Buy, read, study these books (the second is especially for V8 swaps):
If you can't put out the money for these books, then you don't have a chance at affording the swap; If you are not prepared to study and *understand* the applicable wiring diagrams, it will not work. Sell the car, buy a car with the engine already installed; you'll be way ahead. All projects take longer and cost more. Engine swaps are worse. Make sure you have enough pennies in the bank before starting so you ain't stuck half way. If I haven't scared you off, then you're crazy. Go for it. I know I'm crazy, but am I crazy enough? Hmmm...
From: Dave Hewson
V8 Archie also does V8 conversions and sells do-it-yourself kits. If you are interested in a V8 swap, there is some good information on his web page. http://www.v8archie.com