Maybe you should mention it is a 87 cradle for a 88 Fiero (?)....
I think the 88 cradle is different so you likely have to swap suspensionparts too. the 3.4 should bolt up to the 2.8 mounts with no mods (if I am right). Starter has to be moved. I guess it will take more time to adapt the 87 cradle then the downtime of your Fiero when you have to switch engines on the 88 cradle...
(I might be interested in the cradle if you are not going to use it. I have a 87GT and also looking for a spare cradle for a swap)
updates on the GTR at PFF: http://www.fiero.nl/forum/Forum2/HTML/038785.html http://members.lycos.nl/fierofiero/html/fiero.html
1987 Pontiac Fiero GTR in progress
1969 Chevy Suburban