Sal check out
www.pro-gram.com they make aftermarket maincaps to crossbolt any FE block. I believe in 69 Ford started stamping the vin on blocks so what you see might be the vin on the rear of the block. C7ME and C8ME were the std casting numbers for the cj block. With the center freeze plug removed you can see 428 cast inside. You might need a flashlight to see it clearly. The vin code should have a R or Q in it for the cj id. Also check out
www.428cobrajet.org this is the cobrajet registry. It has a great component ID section where they show the details between the std and cj blocks. Casting and date code info also. Let us know what you find.....G.