Jim Smart
October 14, 2005

Fitment Issues
Likely the greatest challenge facing any of you considering a Mod' motor swap is size. The 4.6 SOHC and DOHC engines are larger than the rotund, hemi-head Boss 429 big-block. This presents serious challenges for anyone considering this engine swap. Because the 4.6 and 5.4 engines are considerably larger than the small- and even big-blocks we are used to, changes have to be made to some vintage Fords before these engines will fit.

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You may undertake special modifications to your compact or intermediate Ford's shock towers to make way for your 4.6 SOHC or DOHC engine; we have seen this performed in at least one classic Mustang. This, however, is not recommended. The best solution is to remove the shock towers and install a Mustang II or strut-based front suspension package to get the space to install a 4.6 or 5.4 in a vintage Ford intermediate or compact. This makes plenty of room for the wide-body V-8s. Another issue is weight. The 4.6 and 5.4 Modular V-8s weigh more than our small-blocks, but are on a par with vintage big-blocks weight wise. This will effect handling and weight distribution. The objective is to get these engines as close to the firewall as possible to help weight distribution. Modular V-8s all use the same engine mount, which keeps things simpler. Our goal is to undertake a Mod' motor swap in Mustang & Fords in the near future, learning as much as we can about fitment.

4.6 and 5.4 Weights
Engine Type Weight
4.6 SOHC 500 lbs
4.6 DOHC 425 lbs (al. block)
5.4 SOHC 525 lbs
5.4 DOHC 540 lbs

Engine Dimensions
Engine Height Depth Width
4.6 SOHC 26" 23 5/8" 26 5/8"
4.6 DOHC 27 1/8" 23 5/8" 26 5/8"
5.4 SOHC 28" 23 5/8" 27"
5.4 DOHC 35 1/2" 23 5/8" 28 1/4"

Bolt-On Necessities
According to Sullivan Performance, there are at least six different castings for the water outlet and oil filter mount. Sullivan suggests the F8ZZ-6881-AA outlet/mount because it accommodates an oil cooler. The Ford factory oil cooler is F8ZZ-6A64-2BA. Both are available from your Ford dealer for approximately $150 each at press time.