[bohmankid]

spacers for what? all you need to put that 80e behind your 5.3 is the 6.0 flexplate if i recall correctly. Also, 5.3's did not come with 80e's so your pcm will need to be reflashed. the 80e's are tough and heavy and well worth it esp. if you're pushing a lot of power. But they kill your mileage. 60e's are good for gas mileage and mild 5.3's. You can mix and match almost any gm motor with any trans. it's awesome.

edit: about the flexplate. could he just use a 6.0 flexplate to bolt it up to the 5.3? or does he HAVE to use the 5.3 flexplate and order the spacer to make it flat? either way it'll work. view my build thread in my sig, post #14 has pics of the bolts and spacer i used to mount it to a th400.