I have a 305tpi and will be replacing it soon with a 350 tpi. i need a new computer box and chip and need to know if i have to buy the 305 computer box or the 350 box. autozone has 2 boxes for the 305. i think one is for the automatic and the other is the 5spd. they don't come with chips though. there is only one box availble for the 350. i am just concerned about the tranny part. if i buy a 350 box will it be pregrammed with for the torque converter lockup or is it all in the chip. can i just buy a 305 replacment box and then install a 350 hipo chip. i am putting in a 6spd down the road.

 

The computers themselves are the same, its the chip thats different.

 

thanks

 

Stop. The different ecms are for Speed Density 730 and MAF 165. Those are the last three digits that they have on their part number. What year is your car and we can tell you which you need. The 90-92 used the 730 and 86-89 the 165. 1985s used a different one again.

If it is a SD car, you are in luck as the early 90 Lumina, Corsica, Berretta, Grand Am, F-body MPFI V6s 3.1s used the same.

Also the earlier MAF MPFI 2.8s used the 165s but I am not certain as to the years as they changed sooner I believe. I am more up on my SD cars. But you can grab them from a wrecking yard dirt cheap from those cars. Just say its for a Lumina. If you say Firebird or Camaro, they'll jack the price up; even though they are the same.