3.8sc swap into 94 Oldsmobile cutlass Supreme convertible

[edbone095]

Hello everyone out there.

Unfortunately Gm has made the decision to discontinue the cam belt tensioner for the 3.4 dohc engine.

What's the feasibility of swapping out the 3.4 with the 3.8sc?

[94 olds vert]

I know it's been done before. I think the biggest issue is always switching the vehicle over to OBDII. But if you aren't going for a Series II L67 a Series I L67 from a Bonneville that is OBD 1.5 might make a better option. 

[55trucker]

The *actuator* was discontinued approx 20 years ago.......finding an NOS piece would be a challenge.

The item IS serviceable..........

[Bake82]

 

Here is info for the the swap based on my own experience of swapping my 88 cutlass w-body.  

 

3800 swap w-body

 

From 98/99 Monte Carlo z34/lumina LTZ with 3.8NA

 

Needed

- power steering lines (buy new)

- Heater hoses (buy new) 

- Exhaust downpipe (or have one made) 

- AC system - all lines/parts from the engine bay (compressors can be from the gtp too) 

 

Best to have from the Monte Carlo/lumina but not mandatory

- engine bay wiring harness

- Cv shafts (buy new if you don’t have them) 

 

From gtp donor 

- motor

- Trans

- Trans cooler lines

- rad hoses 

- Motor mounts 

- Cv shafts 

- PCM 

- Engine bay wiring harness

 

Notes:

 

cv shafts if using an HD trans you need to use the gtp passenger inner with the 1st Gen shaft and outer joint.   If you get them from the Monte you can use the stock Monte drivers side. 

 

Wiring: if you can’t find the Monte Carlo harness you can use the gtp harnesss, and merge it into the 1st Gen c100 connector.  With the Monte harness it comes with the c100 you just need to remove a few pins around and overall much easier but can be hard to find.  You’ll need the GM service manuals for your donor harness and your original car to match the c100 connector.   If using a Monte harness you will probably want to add the BBV wiring.  This will also convert the car to obd2   

 

PCM: you will need to get the vats/security removed(it’s possible it won’t be an issue but be aware it probably will be) and probably want to remove a few other codes.

 

Rad:  you could use your original, but the donor gtp rad will be bigger and fits into the chassis.   I’d say it’s recommended but not 100% necessary.