This will follow the progress of putting a 350 Chevy V8 into a Fiero in place of the stock 2.8L V6. The car is an automatic, but the transmission will also be changed from the stock 3 speed auto (which is pretty weak) to a 4T65E electronically controlled 4 speed,which is hopefully strong enough for the V8. This is a work in progress and not all the details have been sorted out at this point. I'm adding to this site as I make progress, so something that you see early on may change later.

If you have any questions or comments, let me know:



This was the starting point, a 1985 Fiero. "Notchback", 13" wheels, 2.8L 6cyl engine. I think it was in March 2008 when I bought the car and brought it home. Oh, what about the red one shown at the top of the page? Well, I'll get to that one later, but this is the car that started the swap.


First step, get it in the garage for the transplant. The Miata on the lift isn't mine, I was storing it for a friend. Of course they do make a nice swap project with a small block Ford....hmmm....maybe the next one.


The Fiero uses a rear frame cradle that holds the engine, transmission, exhaust system, and the rear suspension. So when everything is disconnected from the car, there are 4 bolts that hold the cradle to the main frame; undo these and drop it out. It has been dropped onto a wheeled dolly to get it out from under the car. Then it was hoisted up onto a pair of sawhorses to start taking things apart.


I took the rear body panels off to see how things looked. Ooops, much more rust than I thought. Oh well, just one more challenge. The upper frame rails were pretty much gone on the lower surface so they were cut out, on both sides of the car, and replaced. Also, the sheet metal in front of the wheelwell and behind it, again on both sides of the car, also had to be cut out and replaced.


New frame rails being formed from .065" wall thickness, 2" square tubing.


New frame rail and sheet metal welded in place. It was later painted black for rust protection. Little did I know that some of the sheet metal shown here, nicely welded in, would be cut out again to make room for the electric water pump...more on that later.


The original engine had fuel injection and computer control; the V8 will be carbureted so I don't need all of the brackets that are in the engine compartment to hold hoses, wires, sensors, etc, so I cut them all off to neaten things up a little. Besides, this saves 1 lb of weight (every little bit counts).


A preview of what is going in. Carburetted 350 cubic inch small block Chevy. A fairly stock "L82" engine, early 1970's vintage. Modifications include roller rockers (stock 1.5 ratio) and mild head porting. The water pump is deleted as it will be replaced with an electric unit.


The stock harmonic balancer must be replaced, since it is too wide and will hit the Fiero frame. It is replaced with a much narrower one. The problem is that the new one has a much shorter shaft portion and does not fully bottom onto the crankshaft step; a spacer is needed to go on the crankshaft first. Since I don't need the old balancer, I made a spacer from part of it. I chucked it in a lathe...


...and cut off the shaft portion. This gives me the basis for a spacer that has the correct inside and outside diameters, and also has the keyway cut in it to clear the key in the crankshaft. Yes, I'm only using the small piece that is lying on the lathe bed.


A bit of turning on the lathe to get it to the correct thickness (and opening up the bore very slightly so it will slip on and off the crank easier) and it is done. This piece slips on the crankshaft against the timing chain sprocket, and the harmonic balancer pulley will then bottom onto the spacer.


Perfect fit! Actually, it is maybe a bit too thick still, but I'll wait until I trial fit the engine onto the cradle and into the car to see how close the balancer comes to the frame of the car. I can still take off a little to move the new harmonic balancer closer to the timing chain cover (but not much closer).

time to move onto page 2 of this project - just click here