I have been searching all day and night around the web and can't figure out if you are supposed to use the 3.4 heads on the 3.4 swap or the 2.8 heads. I would like someone to elaborate a little more on this question.

Then could i just get all the gaskets for the 2.8 since the 3.4 is almost exactly the same?

The heads are exactly the same. But you will want to use the head gaskets from the 3.4.

Ditto

Head gaskets for the 3.4 are slightly larger, I think. Ask your parts house to look up the numbers for the 2.8 and 3.4 to see if they're different. Also, the temp gauge sending unit is in the wrong place on the 3.4 heads. The Fiero sending unit needs to be above the number 5 cylinder. Since the heads are identical, you can swap the position of the heads and not have to fret with trying to remove the pipe plug from the head.

I swapped the heads, broke a socket trying to get that plug out.

quote Originally posted by ragging_fiero: Then could i just get all the gaskets for the 2.8 since the 3.4 is almost exactly the same?

No.

More specifically, ragging_fiero, you'll want to get the head gaskets for the 3.4L not because of the cylinder heads --- which are indeed identical for 2.8L and the 3.4L --- but because of the 3.4L engine block's wider-diameter cylinder bores.

As for the other gaskets or seals you'll need (not always from the 2.8L), the archived thread on Pennock's Fiero Forum which is titled, Gaskets for 3.4 pushrod - what to order ( https://www.fiero.nl/forum/A...110502-2-108252.html ) presumanly will be of value to you. (However, it likely would be prudent to have your parts supplier check the current part numbers for the gaskets listed in that thread, because part numbers can change over time, and that archived thread was written nearly four years ago.)

Good luck to you with your 3.4L engine swap project.

Something I need to clarify in project34's link. In my first post, where I referred to using the 85-86 or 87-88 water pump, I should have actually said that if you were using the 85-86 timing cover or the 87-88 timing cover. The 87-88 2.8 timing cover and oil pan have the same design as the 3.4 pan and will intermix. The 85-86 2.8 oil pan and timing cover are slanted at the front and must be used together. If either of the 85-88 oil pans are used with the higher volume 3.4 oil pump, the baffle will need to be notched, as I noted. If you need measurements and a picture for notching your 2.8 pan, email or PM me and I'll post, just in case I'm not watching this thread.

When I did my 3.4 Camaro swap I used a fiero 2.8 gasket set and ordered the right head gaskets. I also reused the 2.8L pan as my 87 timing cover was different than the 92-93 3.4L.

Also I resused the fiero intake manifold since it has the startup injector and matches the haness. I think the 3.4 manifold has only 6 injectors (not 100% sure anymore as its been 10 years).

I think that pretty much is the difference.

I would use that as an opportunity to switch the coolant temp sensor to a 3-wire version from a newer vehicle and send that output to the temp gauge.
Head temp isn't as important as coolant temp and newer cars just display coolant temp...