I have a 85 IROC-Z with a 305 TPI and I am putting in a 406 I already have built the motor came out of a 77 four wheel drive truck will every thing bolt up? and will the stock injectors and throttle body work for now? Thanks

 

Man, people aren't very talkative today...

"Bolt up"? You do know the 400 is externally balanced, so you need to use the harmonic damper and flexplate that came on it. Those flexplates are typically 168 tooth, and will likely cause "issues" in your 3rd gen. After that, it's dependant upon which heads you're using, but everything else should bolt on.

"Work" is a relative term. It will probably start and run, but won't exactly wow you performance-wise. I've never heard glowing reviews of the '85 TPI system, so it may have fits with the extra displacement. You'll probably also need an adjustable fuel pressure regulator to get it half-way running right.

What exhaust are you using? What cam? Those will greatly affect how the whole thing works.

Injectors and TB are just the tip of the iceberg. The base, runners, and plenum will all restrict flow to your 33% displacement increase (they are restrictive to a 305). You can port the base & plenum, but runners have to be replaced.