I am going to attempt to start the 355 motor swap this weekend. I know that some of the lo3 sensors will swap to the 91 l98 speed density motor that I just had built. Anyone know exactly which ones will transfer over? I have all the original sensors for the motor but some of them are in pretty bad shape. how bout the starter from the 305 to 350?


Also I realize that the fuel pump and fuel lines will have to be switched as well so I was planning on checking out the local junk yards to pick up a newer tank and fuel lines and of course order a new walbro fuel pump. I hate changing the fuel pump/tank in these cars but it looks like I will have to do it one more damn time. Does any one know if a fourth gen tank/fuel lines will work in our thirdgens. Only reason I ask is cause here in Austin there are thousands of fourth gens at junkyards but no third gens and I really don't want to pay $300 for new parts that will work just the same. Sorry for all the question but your help is greatly appreciated.

 

Starters are the same.

The rest of this is 2nd hand, so believe anybody who says differently. My info is coming from a bud who converted his '90 RS LO3 to '91-style SD.

Pump will have to change. Fuel lines up to engine compartment are the same, just the flexibles to the engine change. Not sure what you mean by "all the original sensors for the motor" - the LO3 or the L98? Either way, he bought all those new from dealer (including hoses, sensors - he's funny that way).

I don't think 4th gen parts are going to help you much.

Hope that helps some. If nothing else, gets you back to the top.

 

Sorry the new motor has all sensors from a 91 SD 350 (L98). Some of the sensors are from 1991 if you know what I mean (11 years old) , but I have replaced almost every sensor on my current 91 LO3. If some of the sensors will transfer from LO3 wiring harness to L98 than I was hoping someone could tell me which ones would, so I could of course put the newer sensors on the new 355.

I figured the starters were the same but just wanted to verify cause I will use the flywheel that came from the original 350 and reuse the new starter from my 305..


As far as gas tank is concerned I was trying to get out cheaper by picking up a used one over buying a new one. (the tank I have now is dented from when my friend and I changed the last fuel pump, We got pissed off and kicked it a few times when we finally got it out. HEHE it was fun but now I wan't to replace the tank we kicked in since I gotta do this again)


I have called I think every junk yard in Austin and this is what I get, "well we don't have any third gen parts, but we do have a 94 z28 that was pulled in today. I think the parts are all the same" Again this is the usuall statement I get from Joe Shmoe at the local yards. I guess after hearing this for ever I figured the next closes thing was a tank from a 93-2002. It's either that or I will have to buy new one which I really don't want to do, but may have to.


I know this topic 305 to 350 has been beat to death but this is my first engine swap and I want to make sure it is done right the first time without spending too much extra money in the process and hopefully without too many suprises along the way. Again anyones help is greatly appreciated.

 

I'm kinda curious about that too. When I was tank shopping, I was comparing 4thgen and 3rdgen tanks at the yard side by side (they pull all those and stick them in a warehouse) and they seemed identical except the filler neck. But that was a while ago, so my memory may be a bit faded on that. I thought about going ahead and getting the 4thgen tank (since it was plastic) but decided to get the 3rdgen tank to avoid any possible hassle.

As far as the sensors, the knock sensor won't work, but the MAP sensor and the rest of the sensors should. Well, the TPS obviously won't since they're made throttle-body specific.