Depends on your definition of "Bolt In". But in short, no.
If you have all the parts, the 2.8 V6 from another Fiero is bolt in. but youll only gain 33-38 HP. You could swap the raw engine for that setup out for the 3.4, and it's still bolt in. But you don't really gain much HP, but you do gain a lot of low end torque. Maybe, on a good day that will gain you maybe 20 more HP (realistically 50-55 over the duke) because the Fiero's intake is so restrictive against the increased displacement.
This is about it for the direct bolt in swaps. Even then, you'd need the bulk of the back half of another Fiero to make it happen.
Going a little further, you can move up in the family of 60 degree V6's. The 3100, 3400, 3500, 3.4 DOHC and 3900 aluminum headed motors do bolt into place on the Fiero's cradle relatively easily using stock V6 Fiero mounts.
But, they require a myriad of extra work to make them function. They usually need a custom dog bone mount (by the strut tower) a completely custom wiring harness, a complete exhaust system which usually needs to be custom built. And they require a new fuel pump at this power level. But the payoff is well worth it! You can expect 30 MPG or better on the highway with any of these motors, most of which will also net you from 93-148 more HP than the duke
The 4.9 V8 and 3800 engines reqire more mounting work in addition to whats outlined above but very similar effort wise.
The Quad 4 is more difficult as it needs a different transmission, and more custom mounts, Exhaust is difficult to do elegantly and quielty.
As an example of a "bolt in" take a Chevy 283 195 Hp and swap it for a 327 350 Hp. No additional parts or fabrication needed. I guess I'm dating myself with that example................. I have a nice 4 cylinder car available but I would like some additional power. Looks like I will look for a nice v6 car.
As an example of a "bolt in" take a Chevy 283 195 Hp and swap it for a 327 350 Hp. No additional parts or fabrication needed. I guess I'm dating myself with that example................. I have a nice 4 cylinder car available but I would like some additional power. Looks like I will look for a nice v6 car.
If you swapped the Chevy 283 to the 327 they you have all the skill needed to do a 3800SC swap. You can buy all the conversion parts needed and you can have ~250hp stock - 350hp performance with the M90 SC or 350hp - 600hp with a Turbo. The swap is well documented and the community is here to help with any issues.
I have no doubt I have the skills to do a swap but it has been 50 years since I have done one and the body may not cooperate. Thanks for the replies- just the information I was looking for. Bob