ok, i completed my swap from a 305tbi to a 350 tpi (which is awesome)!
now, the motor was a 350 MAF. im running a MAP (speed density) since my camaro is a '91 and has to match up with the system years. if i remember correctly dyno don provided me with a 305 PROM to put in the ECU, no biggie it runs pretty good and i guess all i need is a tune to bring out the best?...however, i found the 350 ECU from the donor car which still had the PROM in it and decided to swap it for the 305 chip thinking it'll run like it supposed to...bad idea i think. as soon as i started it up it was idling HARD and ROUGH and sounded bad, like as if the timing or firing order was off. so i shut it off, scared to drive it like that.
so, is this bad? how would it not run smooth since it came from the '89 350 tpi that I now have in my '91?

the only thing i can conclude is that maybe it wont preform like it supposed to because it was in a MAF and now im running a MAP?

If anyone can help me out please, or steer me in the right direction that would be awesome. im not sure what to do...keep my chip i have now and possibly get a tune in the future...buy a performance chip...buy a tuned chip with my engine specs...???

thanks in advance guys..

 

You got it ;
the tune for MAP is completely different system (6E vs 8D ) to the tune for MAF.The only thing the same is the proms will interchange in the ECM
For starters , the ECM's are different ( 165 vs 730 ),the MAF has a elec spark control module which you will not have in your MAP car ,different knock sensor.

Have you got a 350 MAP TPI ( not TBI ) KC installed?
You need a stock 350 prom for a MAP car and the matching sensors to work correctly

 

ok, so i am on the right track...thanks for the info btw.
when the swap was conducted i used a ECU box from a V6 camaro, and used the V8 prom chip from the one that was provided for me by don. he also provided me with a knock sensor....not sure what exactly it came off of.

so, if i get a 350 TPI prom chip from a MAP car it will run like its supposed to? would it have to be the same year as the 350 TPI engine i got out of a bird??

not exactly sure what the KC's are

 

I did a similar swap I put a 90 formula 350 in my 87 formula that had a 305 with a carb.I bought a 88 donor car changed the harness and used the TPI off the 88 with MAF. car started an ran great now going to put in a forged 355 with accel intake and runners and cnc machined plentum and 58mm TB TPIS cam trickflow heads an the notorious blue bottle. running MSD ignition system.

 

i'm going to be swapping my 305 cfi out for a 350 tpi. i have the wiring harness and computer for an 85 with the maf sensor, but the tpi setup i have has the map sensor. can i just swap the map for the maf so i can use the harness and computer i have? i know the prom still needs to be changed. but are there any other sensors that i'd have to change, or is it all the same except for the maf and map?