OldCelica

The 305 in my Camaro has developed a rod knock so it has been parked for awhile. I just got rear-ended in my 89 Suburban with a 350 TBI (with only ~30,000 miles on the engine) and it is totaled. I would like to pull the 350 out of the Suburban and put it into my Camaro. I am just trying to gauge what I am in for before I commit to the project. I am looking at this as a possible cheap alternative (the cost to buy back the Suburban is $300) to swapping in a crate 305 stock replacement, not as a significant upgrade. Also, I do still need to pass Oregon smog tests where I live. So it needs to run clean without throwing any codes.

I think that the biggest problem is that the Suburban has a TH400 and my Camaro has the T5. I know that the T5 was not rated for the power of the 350, but I am willing to roll the dice on that one. Although the Suburban was rated at only 190hp so that is only 20 over stock and well under the advertised 300hp rating of the transmission. So I think that I should be okay so long as I don't abuse the tranny.

I think that all of the parts I need for the most part will be available from my Suburban (Injectors, knock sensor, etc). However, I know that I will need to obtain a PROM chip that I do not already have between the two vehicles. Can I purchase an aftermarket or junk yard chip (From manual Suburban/truck, Camaro or other w/TBI350?), or do I finally have an excuse to start burning chips?

I know that I will also need to get an ESC module for a 350. Does anyone know if the one in my Suburban will work?

Am I in for any other surprises that I have not mentioned (fuel pump, radiator, etc.)?

Thank you!

OldCelica

Ok, I have now read almost the entire 305 to 350 swap sticky and I think I have my answer. There is no chip available for my application. Since they did not make a Camaro with a 350TBI, and even if they did, the 350 from my Suburban would likely not have been the same spec. Also, since the 350 did not come out of a stock Caprice, the Caprice chip would not work. The chip from my Suburban will not work in my ECM because the ECMs are different.

So I think my options are:
1. Use the 1227747 ECM from the Suburban and then find a compatible stock 350 manual transmission prom chip from a Suburban/Truck with the same engine.
2. Burn a custom PROM chip for my ECM that will work with the 350 from my Suburban.
3. Go with the dynamic EFI solution.

I know that custom programming is the best way to go, but does anyone know if I can get away with using the chip and ECM from my Suburban. From what I have read the pin-outs between the 1227747 and 1227746 ECMs are the same. I know I will likely lose my shift light, but will it run "okay"?

RBob

iTrader: (1)

Yes, the '7747 is pin & plug compatible with the '8746 ECM. Since the Sub has a th400 the shift light will turn on when the ECM commands the TH400 to downshift (it is ECM controlled).

It will run OK with the '7747 ECM. Not sure if it will pass emissions as they aren't as strict on the trucks.

RBob.

dmccain

iTrader: (2)

You can get away with the stock chip being you are putting a stock engine with the same identical cam back in it. May leave a lil power on the table with the 305 tune but it should run fine. A friend of mine is running a stock vortec 350 on his 305/ 5spd tune and he says it seems to run fine. I would look into getting a custom chip made but you may be happy with how it runs.