I have an 85 Trans am w/ an LG4 305 (4 bbl). Also have an 89 Camaro with a 305 TBI (PO claims its a swapped in 350, but i have not yet verified it , probably isn't however). Seems like everyone claims their Camaro is either a HO or a 350 and few really are. The T/A motor runs poorly and has blowby, so I am entertaining a plan to swap the Camaro TBI motor over. I prefer TBI to a carburetor for drivability anyway.

I have a few questions 1) Are the fuel tanks in these two cars the same? I will need to use the sending unit, pump and fuel lines from the 89 car, but not sure if it will drop into the 85 tank 2) I know I will need to use the engine harness, ECM, and fuel pump wiring from the Camaro , but are there any other wiring issues (specifically under the dashboard) to be concerned with? 3)Does the 85 TA have a VSS? If not will the 89 ECM function w/out it? I have several GM factory service manuals for similar vehicles to help sort out the wiring. I plan to get one for the T/A as well.

Since I have a complete running donor vehicle, I figure this swap is very do-able.. just looking for a little guidance from those that have done it already. Thanks
Jim

 

The RS has the L03 in it. It was rated at 170 HP. No HO, but more then your current LG4.

I think the sending unit and pump will fit the 85 tank, but with both tanks outside the car, you can always just swap the camaro tank in, unless it was a rear-ender. I think the biggest differences through the years was the ammount of baffling provided. I cant see any huge issues with the wiring since you have a complete doner. As far as the VSS goes, I believe that both the older CC carb cars and RS' up to 89 had the cable driven speedo/VSS, so that part should be a direct swap. 90+ had the different dash, electronic speedo, etc.

 

Thanks for your response. Sounds pretty straightforward. Only problem is dring the swap I will have 2 cars that are immobile. I only asked about the fuel tanks because the T/A tank looks alot better (lif ein the rust belt is tough on gas tanks/lines/floors etc)
Jim