Shock Tower
As told in the History of the Mustang, my history of this Mustang, the plan was to convert the engine bay into a Boss 429 engine bay. As far as I could tell, the most obvious difference with a Boss 9 are the shock towers. The guys at Kar Kraft modified 428 towers by not only cutting and reshaping the face of the towers but they were also pushed back into the top side rails to gain that much more room. The Boss 429 is 31 inches wide. The 427 SOHC is an inch wider at 32 inches. For a little perspective, the 428 FE engine is 27 inches wide.
I’ve heard and read discussions claiming that the Coyote engine is the widest production engine from Ford at 36” wide. I did a little searching and on a Ford performance site, they list the Coyote at something like 36X44.5X36. People have mistaken this as the dimensions of the engine. If you read closely, it’s the dimensions of the packaging that the engine is delivered in. The Coyote is actually 29 inches wide. I’ve read that from several sources but this Engine labs site is the most conclusive in my book. For the record, the DOHC Modular engine is 30” wide.
Who cares? Though I probably wouldn’t do it, with the Boss 9 shock towers installed, I can drop just about any engine in this car.
Ok, let’s get this blog back on track.
The original plan was to hack the existing shock towers to do the job I needed accomplished but after reading a bit, I found that the stock towers my car had weren’t even up to that task.
The early Mustangs have a tendency to crack their towers near the base. Later towers were reinforced with a “girdle”. I also learned that the Boss 429 cars started off as 428 Cobra Jet cars. I went looking for a set of salvaged 428 towers.
The next search was for pictures of Boss 429 Mustangs with empty engine bays and fairly clear shots of the shock towers, I know they had been modified but in what way? Since I was surfing the net, I thought, what the hell, why not see if someone is parting out a 69 or 70 Boss 9? It’s an incredible long shot but I’m clutching for straws anyway so why not?
During my impossible search, I ran across a two year old ebay auction that had timed out. The auction was for a set of reproduction Boss 9 shock towers. From comparing the pictures of Boss towers that I had found and the pictures of the auctioned ones, I knew I was onto something. I sent a message to the seller even though it had been a while and I was rewarded with a reply. The seller is Kevin Manley and he has a business in Minnesota called Kevin’s Klassic’s and he restores Boss 429 Mustangs. Kevin confirmed that he had sold the towers at one time but hasn’t for a while. However, if I was serious, he still had the parts to make a couple of sets. Long story short, I bought a set and even had them at my house before I even had the car in Los Angeles.
OG Mustang tower in front, Repro Boss 9 Tower in the rear
Reverse angle
I know most people would have skipped all of this and just gone with a Mustang II front suspension and shock tower eliminator kit. I had even checked out a similar kit for a 64’ Fairlane but when it came to the Mustang, I wasn’t interested. The engine bay with the eliminator kit is as exciting as the concrete lined LA river. It’s a giant irrigation canal. I don’t find canals all that exciting. Yes, the performance is supposed to be better with the double wishbone controlling arms and there’s more room around the engine but I couldn’t go there.
In my last post, I had replaced the fender apron. That was something I had never planned to do. This was supposed to be a quick tower swap and the car would be back on the road and I would upgrade sections of the car as necessary and as time permitted.
Finding rust eating through the fender aprons and into the tops of the shock towers changed my plans.
So with the aprons replaced on the right side, I wanted to see how the new tower looked in the car so I started work on removing the right shock tower.