I am trying to I.D. my TBI motor, but cant get to the casting numbers and whatnot, but had this idea. If it were swapped to a 350, you would need some parts changed to make it run correctly, right? Like the ECM would need to be swapped. The car runs like a champ, gets good gas milage, tons of power, so I would imagine the ECM matches the motor. In theory, couldn't I lookup the part number on the ECM to see which motor it goes too? Like I said, the car runs perfect with tons of nut.

 

That would work, or if its easier for you the casting number on the head will do the trick.

 

The ECM will be the same. You could look at the actualy chip in the computer, and look at the code from it. It should tell you which motor the chip is for.

 

Take a look under the valve covers for head ID and look at the top part of the block just behind the drive side valve cover. If you cram your head back there with a flashlight you should be able to see either a 5.0 or 5.7 raised into the the block.

 

but cant get to the casting numbers and whatnot :read:

 

Ive tried to look in the back 3 times now, but two problems. Theres a huge wiring harness that wont move out of the way and theres alot of sludge build up back there.

I could look under the valve cover easily, but cant you run 305 heads on a 350 block? i know it's bad to run 350 on a 305 block. I guess it would narrow it down a little, if they are 350 heads. If they are 305 heads, I still couldnt tell for sure.

Im going to dig around a little more this weekend to try to get the suffix code from behind the ac unit. Ive tried looking for that one 4 times now. Of course with my luck the deck will have been shaved.

 

If you're going with that theory then you could just as easily have a custom chip and not be able to tell from that either.

 

I do know it has a custom chip already, but I thought maybe the ecm module itself would need to change. So I guess it seems if a 350 were to be swapped in, nothing needs to change except the block and heads. The car still has the stock manifolds and smog stuff on it, but I assume those would blot up to a 350 just as easily.

 

Well thanks for the advise guys, but I managed to get the casting numbers off the back of the block. 14093627 comes up with an 87-91 305 2 bolt main with one piece seal. I assume its the original motor, since it matches what its suppose to have. No way of telling from that number if it was an H.O. or not? I figure its not since the car has a 700r4. (but I could hope that an HO was swapped in...