Need help to decode motor

[sprint289]

76 Bronco Ranger, motor has vibration at 1000 rpm's i think its had a motor change. V8 it has grey valve covers, i need help decoding block, numbers above starter are EOAE below that is D3 6 or G not sure. i'm thinking wrong flywheel maybe. thanks

 

[tailpipe]

E=1980s, 0 year of decade, A=ford alphanumeric value for Ford full size vehicle, E=part.

Decoded=1980 engine part/block. One thing of note is that the number is unique to the original year of introduction. If the part didn't or hasn't changed it will retain the original number. There is a second set of numbers that tell the exact day, month and year the part was made/cast. The typical casting date looks like "6M08". You will usually find these on a riveted tag, stamped, or cast in the part. Your D3 number is a bit out of order from what I'm used to seeing so that may not be the casting date. Below is how the dates are decoded:

Breaking down a casting date: 6M08
6 = The year of the decade. "6" for 1986, 76, 66 or what ever
M = The letter of the month. (December) (A=Jan B=Feb etc)
08 = The day of the month. (8th)

Hope that helps

 

[sprint289]

vibration

Thanks tailpipe, my problem is the gray valve covers, makes me think its a 83 or newer motor. don't feel vibration on road, think i'll just drive it. One more question how to i determine what weight balance i have on front of motor, 28 or 50 oz i've read that may tell me something and its easier to check than flywheel. Thanks

 

[tailpipe]

302s changed to 50 oz balancers around 1983 (someone check my memory on this). You can see the difference in size (thickness) very easily, obviously the 50 being much thicker all the way around. If my picture attaches right you will see a 28 on the left and a 50 on the right.

 

[jckkys]

The '83 up valve covers were much better than earlier types so they could have been put on earlier heads. The dampers can be hard to sort out. The 50oz. on 302s introduced in '82 were usually the 4 bolt type. 351s on the other hand kept the 28oz. balance and the 4 bolt dampers from 351s fit on any 289-302. The after market sells 50oz. 3 bolt dampers for late 5.0s going into early Mustangs, Broncos etc. Fly wheels and flex plates can also be either 28 or 50 oz. The crank shaft is what would determine the imbalance. If I recall correctly the 28 oz. cranks were stamped 2M or 2MA and the 50oz. cranks were stamped 2MAE.