305 tpi to 350 tpi engine swap questions
 

Hello, I have a 86 camaro IROC with the stock 305 TPI. I just purchased this 86 z28 for a parts car and realized it had a 350 in it. I was thinking of taking the 350 out of that and dropping it in my car. Its carberated however, i was going to use my TPI from my 305 on it. Is there any problem I'm going to run into other then having to buy a new computer. I've never done this before. Any tips are appriceated.

Thanks,
Kevin

RE: 305 tpi to 350 tpi engine swap questions
 

computer, injectors, and knock sensor. there are a few others but thats all i got off the top of my head

RE: 305 tpi to 350 tpi engine swap questions
 

Do you think its worth spending the money and going through the hassle to keep the TPI?

RE: 305 tpi to 350 tpi engine swap questions
 

Instead of a whole computer I think all you will need is a prom and the 305 computer. You will also need an ESC for a 350. But it will run with the 305 stuff, just not to its full potential. Just in case you wanted to replace those items down the road.
Also I would keep the TPI.

RE: 305 tpi to 350 tpi engine swap questions
 

I forgot to mention that right now I have the 305 TPI running in my iroc, i planned on just keeping the intake manifold and dropping the 350 in, does that change anything or do I still need the same stuff.

I just did the same swap on an 89. Here are the componenets u will need.

New or reprogrammed PROM (ECU can be re-used)
350 Knock sensor (has to be for 85 to 89 350. 90 to 92 are different, and 305 knock sensors are different.)
22lb injectors
350 Electronic Spark Control... GM part number 16128261 and AC Delco part number 21647 (16128261). 305 unit is different.

everything else can be re-used an the TPI unit itself is the same physical size for a 305 or 350.

the 305 stuff will work on the 350, but your performance will be very limited. the knock sensor and esc will think the engine is knocking, since a 350 has more compression. also you will run rich because your injectors are larger than what your computer thinks they are. also the fuel mapping in the current computer is set for a 305 which has less compression, so your wont be able to provide the full air / fuel it needs to keep up with the 350.

it is possible to do the swap for now and buy the other parts later. but just keep in mind that that 350 will not have much more power than the 305 untill all that other stuff is changed. it will probably run rich as well and have a little lag.

All you need for the ECM is a Prom (Chip) for a 350 engine. Nothing else for the ECM same for 305/350.
Knock sensor
22# FI
Everything else is the same.

check the year of the block for the 350. 87 up uses a different location for the oil pressure switch and sensor, so you would need to extend the wiring if it is a later model block. there are a few other differences if it is an 87 up, but they should be an issue

hey blackz87,

the ESC (electronic spark control) is also different. they physically look the same, but are matched up with the specific knock sensor they are for. this is a common item that a lot of people overlook when swapping from a 305 to a 350. using the 305 ESC on a 350 will report false engine knocks. it will work but will degrade performance, especially at high rpms.

for anyone doing this conversion.... here is everything you need to know about your swap.
http://tpiparts.net/305_tpi_to_350_tpi_conversion