My friend has an '86 gt that has had some work done to it in the past, but some of the things he was told were done will not work on a production '86 setup. How can he tell if this is still an '86 block in the car, or just what production year it is ? Thanks.
you can find a date cast code, it's a 4 digit code. If you've got a F1SE-6010-AA block for example (1991 revision), you should find a four digit casting on the bottom side of the bellhousing mount, it should look like "2A13", "1H27", something like that. 2A13 on an F1SE block means it was made: 2='92, A=January, 13=13th of the month, 1H27='91, Aug, 27th...etc
what i forgot to put, was to reitterate what jerry said, the casting number won't tell you what car it came out of...the only mustang specific blocks ever were the boss blocks C9ZE, D0ZE..."Z" for Mustang...5.0's from '82-'95 used: E0AE, E4OE(flat tappet), E6SE(roller), E7TE, F1SE, etc...