I have an 84 TA with a computer controlled carb on a 305. I am considering replacing the 305 with a 350, it needs a new motor. I was wondering if the 350 will cause any difficulties with the computer, or passing california smog requirements I think it would be OK but I was hoping someone out there knows for sure or has done this. If so I would really like to know, thanks

 

Welcome aboard.

If it looks exactly like the 305, which isn't hard to do since the engine can be externally identical, and has a reasonable cam in it, and it isn't hard to find a computer-compatible cam (like mine), the computer will handle the 350 just fine and the emissions inspector will never know.

 

Five7Kid pretty much summed it all up, I too am right in the middle of doing this switch except for the fact mine ins TBI -_-..good luck on your swap and have fun with all the little annoying things you run into along the way!

 

I have done the swap using all stock electronic components and it occasionally passes NJ inspection (when the cat is lit up). Computer loves it and haven't had any real problems in 11 years.

Go with a L98 or ZZ4 roller motor if you can.

 

For cheap, convenient and with a warranty the GM Universal Replacement 350 ($1300) is a total bolt-in. Put your intake, distributor, exhaust and accessories onto it and you're good to go. I've done several and they run just like the original 305, pass emissions no problems and put out a nice bump in power beyond any of the stock 305s offered by the factory in 1984.

This is not really a high performance engine- 250HP with headers, not through the stock manifolds. It's got low compression and a very mild cam. But 45 more cubic inches makes up for a lot. 250HP and bunch more torque feels a LOT stronger in the seat of your pants than a sub-200HP 305 that also makes a lot less torque.

Beyond that is the 290HP GM crate motor ($1500) which is the same as the universal replacement 350 above, but with a bigger cam in it (I'd say around 215-220* @ .050 although GM doesn't list it's specs exactly other than lift which is .450/.460"). That might be a bit bigger than you would like for easy emission compliance, but you could probably get it through with a sharp tune.

And then you have the zillions of aftermarket 350 combos, not to mention all the different combinations you could build yourself.....

 

i dunno man...im really, really paranoid about my emissions here in nashville, i dont want to run an aftermarket intake or carb, i want all stock stuff as far as my air/fuel goes...ive had to search for a used intake thats in my 1983 year-range that has EGR, theyre very rare, i run a 4 barrel quadrajet.

 

They're not so rare. I've got one in my garage attic.

I'm sure your emissions requirements are no stricter than mine are here. I just went through the inspection and test yesterday, with a highly-modified engine, and passed without trouble (the idiot running the throttle during the dyno sniffer portion of the test notwithstanding).

Besides, doing what Damon was saying would transfer all of that type of stuff from the original engine to the replacement engine.

 

GM used to build a 350 H.O. (or maybe it was an H.O. 350) that was smog-legal in all fifty states (including, to every one's surprise, California), p/n 10185077. Now for the bad news: it was disco'd some time ago.

However, that engine can be duplicated (or even improved) and, as five7 notes, the outward appearance is virtually identical. And, because GM smog-tested it, it will pass smog.

You might want to even think about going with fuel injection.

 

The standard Edlebrock Performer intake with EGR is also 50 state emissions legal, if you wanted to go with a slightly more performance-oriented intake than stock......