Is there a way to 100% ID a 351M? When it's still in a car? When it's out and on an engine stand?
Bought what I thought was a 351C that someone had put into a '66 Ford pickup. Junkyard markings said '73 Mustang and I noticed D2AE-CA casting # on 2V iron intake, D3 # on the Ford carb, etc. All had me convinced it was an early 70's Cleveland. What has me confused is the assembly date code I found stamped into the blocks front face when I removed the sheet metal cover to replace the timing chain. It was stamped 9J17T, at least I think it's a 9 the curl is missing from the bottom. Since it couldn't have been assembled in 1969 I'm thinking 1979. But if that's the case wouldn't it have to be a 351M?
Dazed and confused as per usual.
actualllly, the 9J breaks out to September, 1969 which is perfect for the new for 1970 351 Cleveland. I am pretty sure (Marti can confirm) that they were punching out 351C's as early as July, 1969 for the upcoming 1970 model year which were typically introduced in the September/October timeframe. You didn't mention (or I missed it) the actual casting part number on the block itself which would also lend credence to a September, 69 casting date. I would think the block would probably be DOAE or some such animal. I am also a huge Cleveland fan and not so much with the 351M (was told the M stood for Midland or Modified, not sure) as there was pretty bad core shift in these blocks and they also had problems with cracking in the lifter galley area. I am pretty sure that when the Cleveland stopped production sometime in 73 or 74, all the dies, molds, machining, etc were sent to Australia.....