Discussion Forum - Northstar Chevelle Club

Derek69SS · Founding Member

'68 SS396 project

Derek69SS · Founding Member

I sent the VIN from the L78 block to Wes at "Lost Muscle Cars" and he found the car is registered in Pennsylvania! I'm now in contact with the owner, and he had no idea was really an L78 car! (but was known to be an SS 4spd car). Unfortunately, he had just spent a lot of money mini-tubbing the car and taking it too far down a modern resto-mod path to turn back and go original.

The one oddity of the stamp is the last digit being double stamped with an 8 over the top of a 7.

7 is lined up in the gang, and the 8 off center assumed to be a factory "fix" from someone forgetting to change the last digit in the gang holder, and stamping the previous car's VIN on it. Knowing the history of the engine, I have no other explanation for the double stamped digit.

I decided to get the car roadworthy this summer, and drive it just the way it was in 1985 when it was last driven.

I cleaned the garage to host a Northstar Chevelle Club "work meeting" to have some help and motivation to try firing up the L78...Despite the problems, it was a fun day with a bunch of great people tinkering on a cool old project...

I also invited Steve (right) to come participate. I bought the car from him after his brother passed away. I saw tears in his eyes several times seeing his brother's old car being the center of attention. It was a pretty special day for him, and he was the last one to leave.

Unfortunately, there were issues with the #1 cylinder. There was a stuck exhaust valve, so we had to dig deeper.

Any hope of firing it up was gone when this HUGE crack in the #1 cylinder wall was found.

Derek69SS · Founding Member

After everyone else went home, the kids and I got to work getting the L78 pulled out so we could drop this rat in its place.

The engine is an unknown, acquired when I bought out a barn full of parts from an estate. It's a 1989 Marine (9XA suffix) 454. Forged crank, 074 "L88" aluminum heads, but never looked too deep into it yet. Borescope through the spark plug and drain plug revealed a few things about it. Pistons are 13cc dome, part number came back as 1971 LS6, so it will only be about 9:1 with the 118cc heads. 4-bolt mains and 7/16" dimple rods, and cam measured out to .510/.525 lift, so a lot milder than I expected from an engine with these heads. Everything looks fresh, heads never been run, pistons clean, and still has assembly lube on the cam. It already had a Chevelle pan on it, so we just dropped it in as-is.

Derek69SS · Founding Member

We finally got it running a couple weeks ago, but during cam break-in we noticed it was getting water in the oil. I figured intake gaskets, so re-sealed those, then tried again... after seeing water in it again, we noticed water weeping by a head bolt, so I pulled all the head bolts and sealed those. When it still leaked, I looked a little closer and found a hole in the casting.

Now, we've pulled the heads, and we're going to throw on a set of 840s that were on the 427 I got with that '64 2dr wagon project I had many years ago. They look to be in useable condition as-is, we'll just swap the springs. They won't look as cool as the 074 aluminum heads, but the 103cc chamber will bump the compression to about 9.8 so I would expect it to make a little more power with them.

This thing has been fighting us every step of the way, and I still haven't been able to drive it yet... good learning experience for Cale though. He's learning stuff at 16 that I didn't learn until NOW at 41.

-- Edited by Derek69SS on Tuesday 6th of August 2024 10:15:03 AM

Derek69SS · Founding Member

As of yesterday, it moves under its own power for the first time in ~39 years. As soon as I thought it was ready for a test drive though, the brake pedal went to the floor.

-- Edited by Derek69SS on Sunday 11th of August 2024 11:35:31 AM

AK · Active Member

Looking nice! I had to double take to confirm it was the same car!

Getting so close.

Derek69SS · Founding Member

It photographs better than it looks in person, but the wheels changed the whole attitude of the car.
The paint is still the early-70s with some rust, flaking, scratches, dings, etc. Needs a good buffing for sure.

Derek69SS · Founding Member

A few small updates... we rebuilt the brakes, replacing some lines, hoses, wheel cylinders, and master cylinder. We also added a fresh coat of orange paint on the drums.

We also rebuilt a carb, which is a 71 dated service carb for a Z16. It runs pretty good, but still have some tuning to do. After a few test miles, it now has a new oil-leak that I haven't gotten it back on the lift to locate yet. It should be just about roadworthy just in time to put it in storage for the winter.