Old School meets New - Supercharged LSA/4L85E into Grand National

Awesome build!

I was hoping someone would guinne pig this swap for me, i'm planning a nearly identical powertrain. Couple of questions if you don't mind:

Why the mast pan? I have read sever places that the LSA pan is a good fit for our cars.

Is the movement of the PS pump and alt absolutley necessary? What about going to a smaller ps pulley like people do who keep the truck accesories? If it's necessary could I get the GM part numbers that are necessary?
Hi Keith,

I went into this project with virtually zero LS experience, so I had to rely on the web and publications for advice. Of course I never saw any reference to the CTS-V (not sure if it's the same as the ZL1 pan) pan until about 5 weeks after the Mast pan arrived. Now I've seen a couple, but no one that's been able to say that they directly did this - it's all been "I heard that pan..." stuff. So I went with the sure thing. If I see a couple more references that seem credible I will post the CTS pan for sale on Maliburacing and maybe here.

If you look at the layout of the PS & Alt on the stock LSA FEAD (acssy. drive package) I believe it conflicts directly with our steering box, maybe worse on mine as I have a 600-series box going in. The 2014 GM Performance Catalog is readily available as a .pdf and has the entire list under P/N 19303242 on page 248 (check out the positioning of those units on the stock LSA diagram to the left on p. 248 as well):

Modified LSA Accessory Drive System, w/o AC
Similar to LSA Accessory Drive Kit P/N 19243525, but designed for
retro-fit applications with a relocated alternator and power steering
pump to provide chassis clearance in older vehicles
• Includes power steering pump and two remote-mount reservoirs;
builder to use the reservoir that provides the best fit for the application
• Requires fabrication of reservoir mounting bracket
• Requires reservoir-to-pump hose
• Can be used with either LSA AC add-on or Corvette AC add-on kit

This P/N is not yet available but each of the listed components is. I was told maybe in the spring it will come out and be <$1000. I bought the PS pump, ALT and 1 pulley off Am*zon and the rest from a GM dealer in the south. PM me for detail.

You have to purchase a Front End Acssy Drive package anyways and the stock one is ~$945. I think I spent ~$1200 and I can point you to a couple parts on the list you probably don't need.

I am cleaning the engine compartment now and also starting to port the blower snout and body tomorrow. As soon as I pass smog some other speed parts are going on there.

You have the transmission yet? I have a friend that is selling his brand new tci six speed transmission for $4,500 comes with ez-tcu and the transmission cooler. You'll still have to buy the shifters and the torque converter.

Posted from the TurboBuick.Com mobile app
Last edited:
Pretty cool. I am planning on a similar build in my Coupe Deville. What pulleys are you planning on running? I was planning on doing a BTR stage 3 cam, I will be on E85 as well. I am just starting to really look into the LSA stuff. I had the pleasure of driving a CTS V with a 434" LSX that went low 10's for a weekend. Awesome power.
Been porting as well as cleaning up the engine bay.

Set up a little porting station:


Here's the snout I just finished - just needs final cleaning:


And from the rear:


Tomorrow I will start porting the blower itself.



  • Snout_front_mini_020914.jpg
    63.2 KB · Views: 259
Last edited:
Should have posted a "Before" picture of the snout before I attacked it:


Pretty congested in there!

Here's the stock blower casing:


Lots of stuff the air has to go around to reach the intake ports.

Here's my first cut on part of one side:


I am going to do minimal cutting with the carbide grinder in this tight space, then do all the medium and finish work with sanding drums on a flexshaft grinder. The electric grinder/carbide bit combo is too dangerous to get into those tighter areas - it will bite - scares the hell out of me. The sanding drum is way slower but if it jumps in your lap you only have to wear a Band-Aid, not pee through a tube the rest of your life :)

2nd cuts with some finer work on the #2 area to the far right:


A closeup of that area:


Slowly but surely.

Last edited:
Continuing to slowly port the blower runner area. I have pretty much finished the shape on the #2 cylinder injector boss, taking a lot of thickness measurements as I go to ensure I don't break through or leave a wall too thin.

I added a little extension to this deep Harbor Freight digital caliper that makes it easy to check thickness on this piece almost anywhere. I am trying to leave minimum wall thicknesses of .125" in the non-stressed areas but have allowed the curves in the injector areas to get as thin as .100".


Using the tool:


Here's the #2 injector boss in its current shape - compare it to the rough cut of #4 on its left:


And from the bottom looking in:


I haven't started on the port lip at all as I need to set the blower body back on the heads and bolt it down, mark it up so I know where to port match it to the WCCH intake ports.

Still cleaning up the engine compartment when I'm not porting, will be stripping off the front suspension and steering this weekend in prep for more cleaning and some chassis paint.

YOU!! are my new Idol..

I just put a 9.55 crank pulley on my friends 2011 CTS-V
IT ran a 12.18 @119mph with just a air box and street tires.

I can see your build going 9's if not low 10's for sure

Been slowly cleaning up the engine compartment so I can start test-fitting the engine and suspension. Also removed the steering shaft tonight and cut the rag joint so I could remove it from the shaft. I'm going to fit it with new Flaming River u-joints to connect up to 670 steering box by the same folks.

I'm d@mned if I'm going to get all the new parts filthy by getting them anywhere near the bay the way it was:


After a lot of elbow grease and scraping with various putty knives:


I'm not going for sterile now, just paintable. The bad news was at least 5lbs. of greasy, oily dirt and grunge. The good news was the frame was completely protected by this crap so there is not a spot of rust anywhere I have uncovered to date!

I still need to remove the harness, take it apart and get rid of the stuff I won't need. I'll replace the wire looms where I can and clean where I can't - I doubt that OE oval stuff is available for prices less than insane. Anyone know a source?

This weekend I am planning to test-fit the front suspension and brakes, then try to have time to test the placement of the motor (with no blower or accessories on it) with the solid mounts on the frame side and the Dirty Dingo adjustables on the motor side.

If that goes well I will do last cleaning and a wipe with acetone then prime. Then spray with Eastwood Chassis Black, the matte (more like a satin than a flat).

The future holds a frame-off build, but right now I need to get this together before the state of CA gets upset about how long it's taking to pass smog. One cool thing was the GM dealer offered to write a letter explaining what I bought and when, to help show progress and plans.

The test-fitting of the suspension will be auto porn for sure, cuz it's all the good stuff I'm been working for and buying for the last year and a half.

Stay tuned.

If you are looking for the oval crinkle wire loom - Caspers Electronics sells it. If you are looking for high temp crinkle wire loom (round pieces), I bought various sizes from McMaster Carr Industrial Supply. I replaced a few sections on my car and it looked exactly like original. I also painted my frame with Eastwood paint with a brush. I used black rust encapsulator for primer and then used satin black extreme chassis. I was very happy with the results. I also spayed the inside of my frame with their internal frame coating. If you do the inside of the frame, paint it first and then the black on the outside.

Your work looks excellent. I can't wait to see more pictures and hear how it runs.

Thanks for that info, Craig!

Last night's photos were the opposite of auto porn :rolleyes:

Here's some of the new front suspension bits that I'll be test-fitting to the car this weekend - I already checked each part with its various mates and everything is cool:


These Wilwood calipers will become my rear brakes later when I figure out what wheels I can fit and save up for them. I already have the 14" rotors but put these 13" ones on (with a different caliper bracket) as the huge Wilwood W6A calipers won't accept a 13" rotor - no brackets available - and I can't fit my current 17" wheel over them. These fit.

The spindles are ATS forged aluminum tall AFX with the ZR1 spindles. The SPC control arms have the Howe modular ball joints.

More steering & suspension stuff this weekend.

Last edited:
Started priming as sections got their final clean with mineral spirits. If you don't prime right away the bare frame starts to rust pretty much right away.


I hope to get some more done tonight.

Got the upper control arm mounts done and one side - the other outside still has some deep cleaning needed. Tomorrow I will wrap up the cleaning and priming and shoot the first coat of chassis black.


Pass. side:


I'll save the inside of the frame for the frame-off work, maybe next winter.

Done with priming. Taking a quick coffee break then busting out the black! I am so glad to be done with this round of scraping & cleaning - the rest of the engine compartment will be easy in comparison.


The most useful tool for this job was a flexible stainless steel putty knife. I also got 5 rolls of the blue shop paper towels on sale and have used almost 4 of them so far. I normally use shop towels but not for grease because if you try to wash them it will ruin the washing machine (or at least create a 4-hr. cleaning session). Luckily I learned that lesson before I was married.

The most important tools have been nitrile gloves (from Harbor Freight) which are good for most painting-related chemicals and a good quality gas mask - mine's this 3M one:


Oh yeah, and safety glasses as well. The solvents in good paint (read the Eastwood label sometime) pass through your eye like it's a cheap windowscreen.

I used mineral spirits for final cleaning and the nitrile gloves are rated Excellent with mineral spirits. The old days of cleaning stuff barehanded in gasoline are long-gone!

Off to paint. As soon as this black is dry I can do some cleanup then hang one side of the suspension. That's the fun part :D

Finished the front frame paint:



And started test-fitting:



Then slung on the brakes:



Big day!

Steering box, front anti-roll bar and passenger side test-fit in the next couple days. By then my new centerlink should be in.

Are you able to swap the LSA supercharger lid for the ZL1 lid? I have a friend with a LSa engine in his rod and wanted to swap it over. Do you know what parts are needed to convert it over?
The ZL1 lid and the red cover looks great!
EDIT UPDATE: Found conversion kit...
Last edited:
Great work and doing it right by cleaning it up and then install all the goodies! Looks like you spent quite some time researching and working out the details of how you were going to put this all together. The final results will be awesome by the looks of this.