It needs a lot of work, overheated bringing it home, heater core, ac, radiator problems, skips a beat going up steep hills

I dunno all the exact problems but rather than do every little thing one at a time in cramped conditions I'm tempted to just gut the thing and clean it up, pull the 305 and put in a fresh 350.

So I'm wondering what it takes to get a crate 350 or 383 smogged in an 86 iroc? There seems to be two completely different facets

1. if it actually passes the smog test
2. the law about it having to be the same engine it came with?

if you pass the smog test, theyll still fail you if the engine isnt stock/oem replacement? I know close to nothing about this, but that doesn't seem to make much sense...

I asked a guy at the chevy dealership and walked away pretty traumatized. This isn't a joke, he said "just take the irocs off the engine during the test and you should be fine, then put them back on afterward", so I was like "thanks man.. gotta go"

 

There's no problem replacing/upgrading the engine in your IROC. Most techs won't know the difference, most won't care as long as all the smog stuff is hooked up and working ... a few, such as the referees will be more exacting - in which case your IROC would be tested for smog according to the year of the new engine, be it L98, LSI or whatever.

I just went through this process with a 1991 Astro van that got a 305 V8 transplant.

 

I agree with Duck on this
You can't tell the difference between a 305 to a 350 to a 383 just by looking on the outside.. but the only way they will tell is if they take your engine apart but they won't do that..
So don't worry much about
I have seen members swap from 305 to 350 and go to the smog shop and pass with flying colors
On my 305HO I have a few mods to the engine.. when I took my car to the smog shop he didn't say anything about it eventhough it sounds alittle cam and the smog guy didn't care, he just saw that my emission stuff was connected and after that pass he did the test and it pass

If you have all your emission stuff connected then you should be okay..

 

Just dont go from FI to carb, if its already FI.Those are part of the emissions package.

 

Thanks guys.. I guess its the typical cali deal where the law is indecipherable/absurd in ink but the guy actually enforcing it is (usually) reasonable. Looks like I'll dress up a 350+ in the stock tpi and emissions.

90% of the repairs I've done so far I ended up tossing the Chiltons book and searching old threads here... this forum is superb

this was handy too: http://tpiparts.net/305_tpi_to_350_tpi_conversion