Thread: 305 -> 350 swap

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Ok. I'd first like to thank anyone who helps me out with clarification in advance.

Im in the process of building up a 350 for my 84 ta. I looked into some shops about doing a swap just to get a ballpark figure to see if its worth paying someone or sparing what little time I do have to swap it. However, I ran into a guy today, who I think is just trying to suck my pocket from what I heard and observed. Shop owners see $$ signs when someone walks through the door in a collar'd shirt and dress pants after work. =)

Anyway.. I was told going from my 305 to the 350, I'd be screwed as far as emissions go. Being a daily driver it wouldnt be a good idea as far as inspection goes. Because of the carb and distributor being electronically controlled it wouldn't be possible to do *legally*.

Ok. The 305 and the 350 are the same block. Why would I have a problem using the same carb and distributor? Eventually Im going to slap a new carb on it. I'm pretty sure edlebrock makes a direct replacement for what I already have (all of the electrical connections in place). The carb on it now is a stock rochester 4bbl. Actually from what Ive seen and heard, these are actually quite the gold mines on ebay. But anyway..

What would be different in the distributor itself electrical wise? I mean, theres probably a chip out there for the ECM, if needed, that could change something with the electronic portion of the timing (if any?). Once again, if needed. So Im a little lost as to why the guy would tell me this.

"If you dont plug them in your check engine light will never turn off and you wont pass inspection" ..yeah, thanks for clarifying that buddy, will it even start? NEXT!

"If you dont use the smog legal headers you may not pass inspection" ..<insert clue injection here>

"There are other options to make it work, but of course they cost money" ..and I can tell you think Ive got a big pocket and thats why this discussion is still going on

Does it sound like hes just after more dollars, or am I going to run into problems using the same distrib/carb?

Im going to research the chip and its controls for whatever I can find. Once again any help would be highly appreciated.

If you swap over all of the 305's bolt on parts and your 350 is a "stock" style rebuild I doubt you will have any "emission" problems. The computers weren't that sophisticated back in '84 and about all they controlled was ignition timing. You can always swap in a 350 chip or have one custom burned if you have any drivibility problems but I really don't think you will.
Mark

Thanks for the clarification. The carb/distrib will be swapped out eventually, depending on how much cash i have after im finished with the swap. If all else fails for whatever reason the chip will probably just be disconnected.

i have a friend that just did the same swap in a Monte Carlo and it took him a weekend to do the job in his front yard. anyone that tells you that it is a hard job to do or things may be different is full of crap!!! everything is bolt in. the shops you are dealing with are just trying to get you for your money. if you lived close enough, i would offer to do it for you at half the cost the shops want. good luck with everything!!!!!

i have a friend that just did the same swap in a Monte Carlo and it took him a weekend to do the job in his front yard. anyone that tells you that it is a hard job to do or things may be different is full of crap!!! everything is bolt in. the shops you are dealing with are just trying to get you for your money. if you lived close enough, i would offer to do it for you at half the cost the shops want. good luck with everything!!!!!

quick fact, 305 and 350 arent the same block.

they are both small blocks but different bore, cam, etc. ur quadrajet would bolt on no problem. same with distributor. as long as u keep the 350 stock u shouldnt be starving for gas.


P.S. not all shops are out just to get ur money

The 305 carb might even be a bit rich for a 350. More air sucks more gas through the jets. It'll run, but will need tweaking to be right.

Here in Ontario, cars more than 20 years old are exempt from smog laws-----are you sure its not the same there? As far as the swap is concerned, its a direct bolt in. The distributor should be an HEI unit in 1984, which does not require any external computer to operate it.---The distributors are interchangeable between 305 and 350 engines. the exterior of these engines are identical---the differences are internal, and would not affect an engine swap. The same carb will work on a 305 or a 350.