Hello All... Planning on a 302 / C4 swap into my 56 Mercury. Have found a few links and threads that discus the swap for the 55/56 Ford. Wondering if anyone can tell me if the 56 Ford 2 dr hardtop and a 56 Mercury 2 dr hardtop share the same frames, suspension, tranny mounts etc. Also if anyone has done a similar swap please feel free to share if you like. Thanks for taking the time... D.E.K
Can't help with differences in the frames but the little Ford is a good swap because there is a good selection of oil pans, motor mounts, water pumps and transmissions for it.
@Dead End Kid There are some known differences, but without digging into the spec books, let’s look at known similarities. For starters, the ‘bones’ are more alike than they are different. Chassis and suspension design are, or are near, identical. Same for the body shell. But more to the point, they both used a range of Y block engines and automatic and manual transmissions. The similarities are so great and the differences so small, Anything done with such a swap on one should easily apply to the other. I have been a decades long admirer of ‘56 Mercs but have never (yet) owned one. Keep us posted on your project, please. Ray
Many similarities. Some differences are 5 on 5 wheel bolt patterns for Merc and 5 on 4.5 for Ford, Dana 45 axle instead of Ford rear axle, wider brake shoes, different brake drums. Possibly shorter engine compartment by 2 inches, which should not be an issue with a 302. Very unusual transmission mount/E brake mechanism mount on Merc. Merc chassis is longer than Ford. Check your front crossmember below the radiator very thoroughly before even starting, cuz repair is much easier with engine out. I am currently working on a 56 Mercury. Join the 52-59 Ford HAMB social group. More info there and it is in short supply for Mercs.
I put these photos on Brushwolf’s thread it’s 55. Ford Windsor is a tighter fit on the Merc. Longer wheelbase but shorter between the firewall and rad support; there is a step in the firewall. Ford also offered a 6 which was longer and you can move the rad too. Merc looks harder to move.
There's more than one way to do this... The now-common method is to use late mustang motor mounts but this mounts the motor high and forward requiring that you move the radiator forward for fan clearance. The main advantage to this is you can retain the OEM firewall-mounted throttle linkage, but if you have a V8 radiator support moving the radiator is a PITA. I did this swap in the early '80s (no 5.0 mounts available yet) and used the mounts from my donor car (a '71 LTD). I built an 'intermediate' adaptor to mate the LTD mounts to the OEM frame mount pads. Here's a rough drawing of what I did.... Top pic is the type of mount I used, the drawing is the adaptor. This is about a 5" piece of 4" channel iron with the side rib cut down at a 5 degree angle relative the bottom to get the mount as low onto the channel as possible. The angle is needed because the LTD mount is 5 degrees different from the frame pads. Drill two 7/16" holes centered in the channel as shown for the adaptor-to-frame bolts and weld a couple of 7/16" bolts in. Drill a 3/8" hole across the adaptor for the through bolt to retain the mount. I also welded a 1/16" thick washer at each through-bolt hole as the channel isn't quite wide enough to fit snugly between the mount 'ears'. Sorry, I don't have the other measurements any more, you'll have to figure those out. The adaptors are identical side-to-side, as are the mounts. These mount the motor as far back as possible and lower than the late mustang mount; the drivers side head is very close to the firewall but will have adequate room. No longer room for the OEM throttle linkage however; use cable linkage like what the Merc above uses. This left me just enough room for a fan attached directly to the water pump (no spacer) without moving the radiator. I'll have to disagree about the Merc compartment being shorter, as I see the above car has room for a fan spacer but it does look like he moved the motor back. A few other thoughts... I used the LTD exhaust manifolds as they had 'down' connections, not the 'rear' connections common on most '60s/70s Mustangs/intermediates. I believe that 289 HiPo manifolds will also work, as well as some late '80s/90s Ford truck if you do a bit of grinding on the ribs. You'll need a '60s/70s type front sump pan, oil pick-up, and timing cover with a dipstick if you don't have them. If you use a driver-side-inlet water pump, the OEM lower radiator hose will fit perfectly. I have a NAPA number for a molded-curve upper hose, but the number is no longer good... And if you still have the vacuum wipers and a dual-diaphragm fuel pump and don't want to convert to electric, the Y-block fuel pump will swap onto the 302/351. The pump arm is slightly different but contacts the eccentric in the same place. I had a 351, those vacuum wipers worked great after the swap... The one 'issue' I had was the OEM temp gauge showed the motor running hot. Apparently Y-blocks run colder; the 351 wasn't running hot, a switch to a 160 degree stat brought the gauge into the 'normal' range. The only 'custom' parts I had was the home-made motor mount adaptors (and an simple adaptor at the trans mount), a speedo cable to match the trans, the upper radiator hose, head pipes from the manifolds to the OEM mufflers, a modified shift arm at the trans to get all gears, and the driveshaft with the right u-joints to match the trans yoke and rear axle. Everything else was either '56 Ford or '71 LTD. You can now buy 'adaptor' u-joints that may simplify the driveshaft, they weren't available at the time. You may need to change the driveshaft length.
I did something like that (build your own adapter to use part of a Ford mount and part of a Chev motor mount to install a SBC in a Toyota Mark IV chassis. True story... Got me thinking that many of the mounts off other year cars sometimes do have some negative consequences to use them. Like the engine sitting higher than optimal, or firewall clearance not ideal. One of the engines I am considering trying to install in a 56 Merc is a 400M with earlier 351 Cleveland heads. There appear to be a lot of obstacles including motor mounts, clearance to steering box, etc. But, maybe not.. If you prioritize steering box clearance with whatever manifold you use, maybe that is the way to go rather than engine mounts first, then exhaust.. Then custom make your mounts to fit the engine with those clearances established already. More work with an indeterminate outcome, but food for thought for me anyway...
We just put a 302 and C4 in my 56 merc. Used Fatman Fabrications engine/trans conversion kit for the motor and used part # TRD-6521 trans crossmember from Summit for the trans. FYI- When I tried fitting the Cleveland in I could not make it fit between the frame rails. I was a teenager at the time so I was just faking it (Like I do today) but I have seen a Windsor in a merc before so it must be doable.
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