Hey guys, I've got a 92 formula 305/T5. The 305 just recently crapped out, and instead of rebuilding it, i'd rather just put a 350 in the car. To be honest this is my first car I've ever owned to have something different than a carb. At the restoration shop I work at, we strictly only work on older Chevrolet muscle cars. Nothing with fuel injection. So I just want some advice before I dive into this. After doing some reading, it looks like I will need 22 lb injectors instead of the stock 19 lb injectors. I was thinking I could change the injector size in the PROM, not sure though. You guys can tell me if i'm just crazy on that. Either way, I would rather have the bigger injector in there. I noticed the knock sensor looked the same..is it? I am assuming that it is NOT the same. Also, I am somewhat confused about the ESC module. I read that the ESC module is contained in the PROM on the 90-92. If this is true, than I won't need to worry about it if the new 350 is a 90-92, along with the PROM. The ECM looks somewhat universal between the two motors, I just have to get the correct year for the motor. The PROM is confusing to me, I know it all depends on the ECM type and the transmission that I will be using. I will be keeping my T5, however it will be getting rebuilt, as its completely shot. Iv'e read a little about beefing up a T5, that'll most likely be my route. I'd love a t56 but I don't have the money. I know the accessories will all work, so i'm not worried about that. So if you guys can help clarify these things with me, that'd be great. I know I don't have much posts, but I have done a ton of reading on this site and it's really a great site. Thanks guys!

 

Also, if there are any tips/tricks/things I should know that would make this swap a lot easier...that would be great. Thanks again.

 

The actual motor swap is no more difficult than falling off a bar stool. The tuning, as you've realized, is the problematic part. The learning curve is pretty long and kinda' tricky. My advice would be is if this is going to be a one shot deal, find a competent tuner and take it to him. If you're hell bent on DIY, there's a wealth of knowledge on this board. However, you can't be impatient/lazy/a technodunce... like me!

 

Yes, well i'm sure several guys on the board have done this exact swap. I searched for exactly what I did, and didn't find much luck. Maybe i'm not doing it right? I have found other sites to have some help/advice but not explaining things as well as this site usually does. I know the motor swap itself is pretty easy, I have already had the motor out of the car once, and I know the 305/350 both bolt right in. I'm not worried about that as much as all the electronic "stuff". I'll be honest, I do not know where to begin with the tuning etc, like i said earlier, never owned anything but a motor with a carb on it...and thats what i'm comfortable with...however I would love to complete this, and gain a little more knowledge about my car as well. I love it.

 

You could retune for smaller injectors ( not recommended ) but larger injectors are installed by the factory for a reason

Electronics are straight swap like for like but you need a 350 TPI (90 - 92 MAP ) knock sensor and a 350 TPI (90 - 92 MAP ) memcal ( prom)

Same '730 ECM used in both the MAP 90 - 92 305 /350 and wiring identical so you need nothing new

Engine has no idea what is controlling it and ECM has no idea what engine is under the intake so years irrelevant.
What matters is that you have the correct combination of ECM / wiring /sensors required for what ever setup ( in your case MAP ) you are installing ;
plus the parts unique to a MAP 350 noted above

Auto tune (on the memcal ) has provision for the convertor lockup so you could use a auto memcal on a man but not a man memcal on a auto

 

I am also looking into a lb9 to 350 roller swap keeping the tuned port stuff like a L98 however my LB9 is 86. Can I run it with an 87 L98 computer and, of course, the bigger injectors and 350 knock. Did the 87 L98 use the maf too? Or am I gonna have to do major electronic mods? I assume a chip company can tune through chip right?

 

yes 22-24# injectors

 

All TPI computers are identical regardless of engine size
ECM # '165 for 86 - 89 MAF or ECM # '730 90 - 92 MAP

It is the tune on the removable chip / prom / memcal that determines what it is set up for which is why you need a 350 memcal when doing the 305 - 350 swap

You swap engines , reinstall your TPI intake , connect existing wiring , install the required 350 items noted above and drive off

 

Good deal. Sounds pretty straight forward. Thanks for answering that question for me. I will write down all the details.