51 merc rear axle

I was wondering if anyone knows if the rear axle from my 51 merc is strong enough to use with a 350 hp plus motor. I am wanting to just have it rebuilt instead of finding one that I have to get cut down.
Thanks
Scott

 

The rear will work but depending on how stock your 350 is . If your engine has more horse power I would consider I stronger unit . Best bet is to talk to an axle shop that is going to rebuild it and ask him to look at the third members condition .

 

it should be a dana 44.. they are still mfg today. in everything from trucks jaguars and 4 wheel drives. for years was the choice of racers. then 9 inch became easy and cheap to come by. most of the 49 to 51 merc had 4.1 or 4.3 gears.

 

A 57 to 72 F100 Ford 9 inch rear end is a bolt in. Even has the same wheel bolt pattern as your Mercury. Way better rear end and a good bit stronger. Same width as the stock 51 Mercury rear end but with a vast range of gear ratios available. A 3.00 gear is very common.

 

It's a Dana, but not a 44. Might be a 41? Smaller and hard to get parts for. Will not stand up to 350 hp.

 

I understood it to be a Dana 44. Anybody have data sources?

The choice to keep or swap may be more about ratio than anything else. If the Merc had overdrive (with a 4:27 ratio rear), you should put in an overdrive transmission or plan on swapping out the rear anyway.

 

The most common is the Dana 41 but i have seen some 51 with automatic's with the 44 and 50 51 wagons and all 49 50 51 baby lincoln. The 41 will work if you keep your foot out of the throttle. The 44 are strong but booth use a same small U joint flange that is on the weak side.

 

Starting in early to mid 50, they changed over from round cover Dana 41 to the flat sided cover Dana 44 for both the Mercs and the F1 pickups. A Dana 44 will have 44 cast into the right rear web of the housing on the bottom side just below the bulls eye. There are new gears available for the ones in the 53 Ford F100 but they might have a little bit different seal & yoke feature than the 51 did but is likely adaptable. Most 51 Mercs had the 3.92:1 ratio but Merc-O-Matic cars had the low one that would give better highway cruise for the automatic. Most Mid Century Mercs had the Borg Warner electric overdrive. Many still have the little metal ratio tag bolted on the cover cap.

 

thanks for all the help. I am going to take it to a axle shop and see if it will handle to power I am wanting to get. I still have not decided on a motor yet. still have frame sitting next to body. I am wanting to get a good roller built first.

 

I'm going to use a 401 Nailhead in my Merc. I was actually wondering about what to use for the rear end too.