John Bzdel's

1988 Monte Carlo SS

LS1/T56 Change-over page

December 2000 Project Updates


12/26/00  Results of the first test fit-up of the F-body LS1 motor:

Tonight I tried the first test fit of the LS1 into the engine bay to understand where the problem areas are going to be.  Here's a summary of my initial observations:

Maybe it's just the black intake manifold contrasting against the aluminum motor and black Monte body, but I must say the LS1 looks nice sitting in there!  I'll snap a few more pic's during the next test fitting!


12/28/00  Results of the second test fit-up of the F-body LS1 motor:

Today I tried the second test fit of the LS1 into the engine bay to with the A/C compressor and mounting bracket completely removed to verify how close the fit of the motor is with the rest of the stock existing hardware.  To assist with comparing measurements between the L69 and the LS1, I am using a spare 400 SBC short block that I happen to have to simplify pulling the complete L69 motor in and out.  As a side note, for those of you contemplating putting a 350 or 400 SBC in your 4th Gen. Monte Carlo, you need to use the stock L69 block side clamshell mounting brackets otherwise the motor won't fit properly!  I verified this by trying the stock 400 SBC block side mounts and they were about 1/8" too large per side to fit the engine saddle mounts properly.   Here's a summary of today's observations:

I believe if I try and re-locate the LS1 forward by about another 1/4" (making it sit 1/2" closer to the front of the car versus the L69) and set it down about another 1/2" (hopefully with the aid of the LS1 Truck oil pan) I believe the passenger side coil pack bracket and #8 spark plug wire clearance problems will be solved.  As a last resort, I can also trim the coil bracket on an angle to match the A/C-heater cover shroud and try to re-locate the coil pack slightly, however, I want to first try to locate everything with factory components untouched and no torches cutting the frame!  I can also center the motor in the engine bay for additional passenger side clearance (remember I mentioned above that the L69 sits ~ 5/8" offset from the body C/L) and may consider moving it slightly to the drivers side anyway to keep the weight balancing similar to stock.  I will have to research this more to understand the ramifications of this.   I will also be contacting Street & Performance to determine if I can get the proper LS1 passenger side high mounting brackets for the A/C compressor.  I am pleased to say at this point that it looks like the frame clearance will be okay everywhere with the LS1 truck oil pan!  Swapping of the pans shortly will verify this.


12/31/00  Comparing a '99 Truck 5.3L oil pan and passenger side coil bracketry to the F-body set-up:

I made a special trip to a local Chevy dealer today so that I could crawl under a '99 Full Size Chevrolet Truck equipped with the 5.3L LS1 derivative to compare its oil pan to the F-body LS1 oil pan.  I wasn't happy with what I saw:

While I was on the phone with SMC Performance about the oil pan situation, Shaun mentioned that the coils are not interchangeable between Truck & F-body on the brackets.  He will investigate several proto-type brackets he has to see if he has a match that will work here.   Worst case, I will modify my coil bracket (at the #8 coil) for adequate A/C-heater cover shroud clearance.


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2001 by John Bzdel