Hey Everyone,

Planning out the winter build while I finish my wife's shed. I believe I am set on this. Again, the goal is a 10.99 at the very least 1/4 on a budget. LQ4/ 4L80E/9IN
1974 Camaro
Is there anything I should rethink? Anything that is overkill or that I am missing?
This is going to be the biggest single purchase of the entire build, so I want to make DAMN sure I get this right.

Rear End
GM F body 1970-1981 Camaro Complete 9" Rear End Package
Housing Center Piece: New Fabricated Big Web (Light & Strong) (+$50.00)
Housing Upgrades: Drain and Fill Plugs w/ Jack Pad (+$55.00)
Housing Upgrades: 1/4" Heavy walled axle tube (recommended for 600+ horsepower or when welding will be done on tubes) (+$30.00)
Housing Upgrades: Internal Gusseting (recommended for 800+ horsepower) (+$75.00)
Leaf Spring Perches *Required: Heavy Duty Reinforced Perches (ideal for high horsepower applications with Caltracs or similar traction bars) (+$50.00)
Leaf Spring Perches Installed *Required: Yes, Installed in Factory Location
New Leaf Spring U-Bolts: Yes Please (set of 4) (+$40.00)
New Leaf Spring Shock Plates: Yes Please (1 Pair) (+$50.00)
Powder Coating: No Thanks - Bare Metal
Axle Spline *Required: 35 (For 600+ HP)
Center Section Upgrade (for 600+ HP): Yukon Pro N Case, Aluminum Daytona Support, 1350 Billet Yoke (+$170.00)
Aftermarket Center Section Traction Device - 35 Spline: 35 Helical Posi (+$389.00)
Gear Ratio *Required: 3.25
Lube Locker Gasket: Yes please (+$20.00)
Bolt Pattern *Required: 5x4-1/2
Wheel Studs *Required: 1/2"-20 x 3" Press in
Brake Kit *Required: 11" Disc Brake Kit - With Parking Brake (+$19.00)
Rotor Style: Plain Rotors
Disc Brake Caliper Color: Plain - Bare Metal
Braided Steel Brake Lines: No Thanks
Universal Parking Brake Cable Kit: Yes Please (+$100.00)




These are the options that I have priced for engine and trans for reference

Engine
Trailblazer SS Intake Manifold - HAVE
Siemens Deka 80LB injectors - HAVE
Chevrolet Performance Parts 12646386 Timing Chain, LS Gen III-IV - $70.00
Performance Racing 1213462 LS Series Trunnion Upgrade Kit - $122.00
LS2/LS7 Plastic Lifter Tray, Non AFM Lifters X4 - $56.00
LS7 Roller Lifters, Set/8 For DoD/AFM Delete - $195.00
Chevrolet Performance Parts 12557840 Harmonic Balancer Bolts - $5.00
LS3/LS9 Engine Premium Gasket Set, 4.080 Inch Cylinder Bore - $129.00
ARP Pro Series Cylinder Head Studs 234-4317 - $311.00
VS Racing VSR50WGD 50mm Wastegate With 4, 6 PSI Springs - $170.00
BTR SK001/T/0560/BB BTR Platinum Dual Valve Spring Kit, LS - $310.00
COMP Cams 54-303-11 LST Series Hydraulic Roller, Stage 2 LS3 - $516.00
Hooker Headers 8510HKR GM LS Turbo Exhaust Manifold - $624.00
VS Racing VSR-400-X80 VSR Billet 80mm T6 Turbo 1.32 AR - $770.00
Holley Sniper 8600041-1 EFI Throttle Body, LS, Black, 92mm - $238.00


Transmission
34200-40K Sonnax Overrun Clutch Valve Kits
88075K McLeod Performance Automatic Transmission Rebuild Kits
COA-102800 OR TCS HP-4L80E-35 4L80-E 300M HARDENED INPUT SHAFT

 

Why the 4.5" bolt pattern? The front should be the standard GM 5x4.75" for all F-bodies. Or do you specifically want a different bolt pattern for the rear for some reason?

My only other thought is that if you are looking for a budget option, you could probably build an 8.5" to hold up in this setup, especially with an auto trans, for cheaper. But I guess it might not be much of a price difference if you don't already have an 8.5" in the car...although I thought that would be standard by '74 in this platform?

 

Right now it has the 10 bolt in it, but it hasn't been taken care of, and this build also includes a disc brake conversion. I am planning on programming the 4L80E to start in 3rd so I can brake boost, then launch and downshift to 1st once it hist 1mph. Not sure how hard that would hit on a 10 bolt, but I feel like it is good insurance to get the 9inch. I won't be making a whole lot of power, so I want to make sure I nail the launches. I know people have done a lot with the 10 bolts especially lately, but I am still wary.

 

The 8.5" 10-bolt is a whole different world from the 7.5" version that folks on this 4th gen forum normally have. The 8.5" is nearly as strong as an 8.875" (12-bolt) and, similarly, can be built to handle considerable power/torque/launch. Obviously the 9" will be stronger, but it will also add weight and be more expensive if you still have a viable 8.5" you can build. Again, I only bring this up because you mentioned "budget".

Still wondering about the bolt pattern - just want to make sure that you're aware the 5x4.5" won't match the stock front (unless you plan to change that too).

 

I take it you're getting this 9" from Quick Performance?? Are there any options to go with coilovers?? That would be a better option than antiquated leaf springs or back.

Are you using the stock ECU and doing the sloppy trans brake??

 

I just installed a Moser 9" for my Mustang LS swap. I had a Quick Performance 9" in my 69 Chevelle. Detroit Lockers in both and aluminum thru-bolt cases. Installed a Currie 9" into our 55 Chevy last year.

Did you run your tire size, trans and diff gear ratios, RPM, MPH through a calculator to see where your gearing should be? I came up with 3.25 for mine which would be about 150 mph at 6500 rpms at 1:1 transmission gear ratio. Would be about right for you, as our engine build is very similar.

I had to drill out my wheels for the 5/8 studs to clear. The only wheels I could find with the proper bs were Welds and they were almost 2K each. Maybe be easier for you to find wheels that will work with this platform?

The rear end does have the back brace, right?

As far as the 9" or the 8.5, I would go with the 9". It is more desirable over all if you ever want to sell it, and if something breaks, you can just pop the center section out and take it to a shop or whatever. Plus, you car will be capable of running 9s and even if you don't plan to do that, the car is set up for it if you ever change your mind or sell the car.

I'd get rid of the leaf springs, if possible. We have a 55 Chevy 210 that had leaf springs, and we got a Currie 9" and converted it over to a 4 link with coilovers. Someone mentioned coilover conversion, and I would really look at doing that.

So for your engine, do you have forged pistons? You are going to gap your rings for boost? I have that same exhaust manifold and turbo you do. Here is how we mounted the turbo and made a bracket for it to sit on. I would do something like that rather than it just sitting on the manifold. Had to find a radiator with inlet/outlet that were both on the drivers side.

 

I meant to do 4.75 so yes, that is what it will be. I left out the back bracing. Is it worth it? I modeled the setup after people that have had similar builds. Believe me, I have resisted the temptation to make posts like this for a while, so I can gather the info. Eventually getting rid of the leafs and doing a 4 link is in the cards, but not until that 10.99 slip. It just isn't in the budget. My last camaro had a Watts LInk in it. Pretty similar to a 4 link, and i know the benefits. Definitely miss that.

Left out that I will also be getting a boxed K member and boxed subframe connectors so i don't crinkle anything

 

Yep get the back brace for sure

 

I don't see any reason not to get the back brace.

I would get 5/8" studs rather than 1/2". The negative is finding wheels that will work with the 5/8 studs. I'd ask the company you are getting the rear end from about it at least.

 

Easy enough to drill the wheels out