I am wanting to swap a 4.3 vortec V6 into a fiero I just got. The current 2.8 v6 engine has low compression(50psi) and does not run. Been sitting for years, was told the timing chain snapped and someone supposedly put a new one in and never got it running and now its my pro-ject-blem). A 3.4 swap is hard to find as the engines are rare in running condition and the V8 is too much. The 4.3 Vortec is perfect, engines are dirt cheap and plentiful, tons of parts. I can run either a carb or a 4 barrel fuel injection kit. The issue I am running into is what flywheel to use? Should I just buy the V8 archie adapter(I do NOT need a full kit, just an adapter plate and flywheel). Theres the Street dreams plate and flywheel. Also sort of expensive. I saw another person just use the flywheel from the iron duke and redrill it and they made their own adapter plate. That is an option(never made one but with laser cut aluminum now how hard can it be as long as someone has some specs for it?). Just wanting information and advice. And yes I looked at the 3800 swap and I am not very interested, same with the 4.9 swap. The 4.3(once it is installed) is much simpler to run and plenty of power. No aging gm wiring and computers and sensors. The car is a basket case so theres no wrong answer. I will not feel bad gutting the engine bay. Thanks everyone!

Edit, 1986 2.8 v6, 4 speed manual

[This message has been edited by Filben (edited 11-01-2024).]

You will need an adapter plate and matching flywheel/starter.

Archie's manual kits use a 1" adapter, 153 tooth flywheel with the OD on the clutch face turned down to fit within the bellhousing. The flywheel was drilled to accept the fiero clutch pressure plate. The thicker adapter plate is needed because the 153 tooth ring gear will not fit within the transmission bellhousing.

Street Dream's kit is based on the old Zumwalt design with a thinner adapter plate (some would say too thin), a flywheel that uses 120 tooth nissan ring gear and a Nissan starter. The flywheel/ring gear on this version fits with the transmission bellhousing.

Unless you are a machinist or have access to lathes and mills, you are better off buying the custom machined parts... and yes they are expensive.

Here is a link to my 4.3 CPI build. I have also have build threads on a few SBC and LS swaps.
https://www.fiero.nl/forum/...0314-2-087174-1.html

[This message has been edited by fieroguru (edited 11-01-2024).]