302/351W V8 into a 6-cyl Maverick or Comet

[ Engine Mounts | Crossmembers | Driveline | Misc. | 351W Specifics ]
The 302 was introduced as the sucessor to the 289 in 1968. Ford has manufactured to 302 for over 30 years, and it still sees production in the Ford Explorer. It is one of the most modified engines ever, and a popular choice for the Maverick or Comet. While these cars had a V8 option, many cars were six-cylinders. This article shows how to convert these "six" cars into "eights."

At the bottom of the page is some 351W specific information that I have compiled. I have not done the 351W swap yet but plan to soon. If you've done it then please let me know how it turned out.

Engine Mounts

The most important part needed in the swap are the V8 engine frame brackets (above left). These parts bolt between the frame and motor mounts. They are easily identifiable from the I6 frame mounts (above right) because the V8 mounts are stamped steel while the I6 mounts are cast iron. These must be taken from a donor Maverick or Comet, or are available new from Crites Industries at or call (740)-983-4777. They list for $89 a pair.


302 Transmission Crossmember
V8 equipped Mavericks and Comets had a unique transmission crossmember as well as an engine crossmember (I6 cars had no engine crossmember). While neither of these items is absolutely necessary, the transmission crossmember will allow you to run V8 exhaust without kinking the pipe, and the engine crossmember adds chassis rigidity.
The only source I know of for the engine crossmember is other Mavericks and Comets (i.e., junkyard).

Autokrafters Reproduction Tranny Crossmember


    You can keep your I6 front springs, but your car will sit lower in the front. You should upgrade to a larger diameter (7/8") sway bar. It would be very wise to convert to front disc brakes at this time also. See my front disc brake article.
    It is a good idea to beef up your Maverick's driveline when you install a V8. If your car had a 170 or 200 engine, the transmission will not fit anyway (requires a bellhousing change). The 250 C4 transmission will fit the 302, but will not stand up to too much abuse (at the least, rebuild & install a shift kit).
    Basically, you should use a V8 transmission if you can. C4 automatics from 302's are easy to find in a junkyard. Any Granada or Mustang small block C4 (pre-77) will work. As far as manual transmissions go, see my manual transmission article.
    All 1970 Mavericks came with a small 7.5" rearend. This rearend is not adequate for V8 use. Find a later Maverick or Comet to swap the rearend out of. All 1971-1977 Mavericks and Comets came with 8-inch rearends, though 71-72 170 and 200 ci cars had 4-lug axles. If you are switching to front discs (and 5-lugs), you don't want this rearend. 5-lug axles will swap in place of these 4-lug versions. Other options include an 8 or 9-inch from a 1975-1980 Ford Granada or Mercury Monarch, a 9-inch rearend from a 1977-80 Lincoln Versailles, or an 8 or 9-inch from a 1965-66 Mustang. All of these rearends will bolt directly into a Maverick or Comet. See my Versailles article for info on a 9-inch rearend swap.


    The wiring on these cars is fairly simple. You can use your alternator from the I6. The other wiring is simple. See my Wiring Diagrams for help.
    The water pump on the Maverick must have the water outlet on the driver's side. You can use a late-model Crown Victoria or LTD water pump. These water pumps are available in both cast iron and aluminium styles. NOTE: You can't use Mustang or truck water pumps, because they are reverse rotation. You must use an LTD pump.

351W Specifics

The 351W is basically the same as a 302 except for a taller deck height. It utilizes a different intake manifold, distributor and oil pan than the 302. The timing cover, water pump, and bellhousings interchange, as well as the heads in some cases. The problem with the 351W is width, it is a very tight fit in the Maverick/Comet bodystyle. Changing spark plugs and installing headers is very difficult. Tubular Automotive supposedly makes 351W swap headers that fit the Maverick/Comet without modification to the shock towers. As of 11/2000 they do not have a website, but here is the contact info:
Tubular Automotive Headers
248 Weymouth St.
Rockland, MA 02370-1139
(781) 878-9875

I installed a 1987 Mustang 5.0L in my 1970 Maverick. If you have any more questions about this swap, or have something to add to my information, feel free to contact me on the Maverick Message Board.