Shocktower modification for big-block header and spark plug clearance.
At a glance it is hard to tell we've modified the engine bay, however believe us that access to headers and spark plugs with the 460 is now a piece of cake.
Yes we hacked up a 1969 Mach 1. If this were a purist magazine we'd expect a flood of hate mail from the "trailer it, don't drive it" crowd. However this is FORDMUSCLE, where we believe Fords are meant to be driven fast, no matter what it takes, including modifying a collectable car to make room for a big block. Besides we think our modified shock towers look better than Fords, and if by some chance Victor sells the car (which he swears he won't) the shock towers can be replaced with new ones.

A 429 or 460 is technically narrower than the FE series motors, which would have meant a little more room for our hands to get to the plugs and header bolts. However with the larger 460 headers and taller valve covers, the engine is a very snug fit to say the least, and turning header bolts 1/8 turn at a time was becoming a major pain in the butt. To remedy the problem we decided to trim back the shock towers a couple inches. While this doesn't sound like much, anyone who has struggled with a header bolt or spark plug in a snug engine compartment knows even an inch makes a huge difference.

Many of you are probably aware, or have probably seen, early Mustangs, Falcons and other engine-space challenged cars converted to coil over and rack & pinion systems in order to shoehorn in a big block. While this is certainly an option, and yields a huge amount of space due to the elimination of the shock towers, we felt it was simply to radical for our Mach 1. Not to mention it is expensive, time consuming, and hard to convert back to stock.

Trimming the shock towers, on the other hand, is a fairly simple operation so long as you have access to a large cutting wheel (or plasma cutter) and a welder. In our case it was Victors neighbor who had the fabrication materials and expertise.

We performed the job a couple months ago, shortly after the Ford Racing 460 "malfunctioned" and was pulled to be sent back to FRPP. You really cannot perform this job with the engine in place.

As the picture captions explain, the steps are straight forward: the "A" shaped shock towers are cut back about 1/2" in front of the shock plate, and then straight down to about two inches above the control arm bolts. At the lowest point we gained about two inches of clearance, plenty of room for two sets of hands to access header bolts and plugs.

Steel plates about 3/16" thick were cut to shape and welded to close up the holes. (While it may be tempting to leave the shock towers open, it is not a good idea as the front end would be structurally weak and prone to flex.)

Using a large cut-off wheel a section of shock towers was cut out. The cut edges were smoothed out and prepped for welding. The opposite side receives the same treatment.
Prepped and ready for welding. The finished job looks better than the originals, in our opinion. Not only is the tower just as strong, it offers a total of four inches more clearance across the engine compartment.


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