3800Pro Forums banner

My latest swap, 92 Caddilac STS!

7.7K views 10 replies 9 participants last post by  the driver  
#1 · (Edited)
My latest swap, 92 Cadillac STS!

I finished this project last week and it took about two weeks worth of time to do. The car is a 1992 Cadillac Seville STS that originally had a tired 190K mile 4.9 slug, it kept overheating and didnt run the best so the owner asked if I could put an L67 in it. I thought about it for a week or two and said OK lets do this. The engine/ trans are from a 00 Bonni, Thanks Ed! It shocked me that really nothing from a bonneville would work in this car and I ended up using W-body stuff such as axles, one dog bone bracket, side trans mount, and a few misc other things. I had to make my own front lower mount bracket and a shorter dogbone for the top. The engine mods are 3.4 pulley, 2.5" downpipe, and fenderwell intake. For the size of the car it really runs well and pulls up top a lot better than I would expect. There was a lot of custom wiring involved in this swap also and I had to retain the stock pcm to keep the HVAC system functional as it relays data over the data stream. The dash also has a digital info center built in and uses pcm data for that also. All in all the swap went pretty well, most of my time was spent driving around finding things that fit! Radiator hoses were a real chore, after my third trip to Napa I just went in the back and started looking at hundreds of hoses and came up with a few that worked, W-body and H-body werent even close to working which suprised me. Here are some pics of the swap.

Image

Image

Image

Image

Image

Image

Image

Image
 
#2 ·
That's great!!
:icon_eek:
I will print this out for the guys at the shop.
I've been a Cadillac tech for almost 17 years.
The 4.9 motor was overheating probably because the head bolt threads pulled out of the block.
Used to see it all the time when the 4.9 was around. NorthStar rules the roost now.
;)
 
#3 ·
great swap i never would expect that in a cadi thing most be alot lighter upfront to anyway great fab work keep it up
 
#8 ·
have any isssues with the stock pcm running the l67?
 
#9 ·
The stock pcm is not running the L67 and wouldnt work for numerous reasons. The stock pcm is still wired into the car, but not the engine. I am using a very modifed grand prix wiring harness and a 99 GTP pcm that I custom tuned to the car. The stock pcm relays data to numorous modules and computers in the car and needs to be in the loop. The blower motor will not run for the heater if there is no rpm referrence signal as it is controlled by the HVAC controller and gets data from the engine pcm and wont properly work without it. The only thing hooked up to it is the map sensor, a coolant temp signal, external trans range switch, and an rpm ref signal. The engine coolant is displayed on the driver info center which is located in the bottom of the instrument cluster and also gets info from the data stream from the engine pcm.