casting # 396021F
heads # J
oil fill pipe # 30714444
on rear of block by crank # 68 F3
intake man # 412753


its my understanding that being an "F" cast instead of a "Fa" cast that its a 68-71 block. does the # on the fill pipe mean 3-olds, 0-1970, 714444-serial#? what does the 3/4" tall 68 F3 mean on the rear?

and any other useful info such as what years did/didnt have J heads, if the intake number means anything, etc. this motor has been built before and in several cars so im trying to identify what all it is and isnt so i decide what parts to keep or replace and the gaskets ill be needing. thanks

 

J heads were used on 73-76 motors only, so they are not original to that block. Since the engine appears to have been cobbled together, the exact year is pretty meaningless. All 68-76 455 motors should use the same gaskets and internal parts. You can find the exact year of the block by locating the VIN derivative on the driver's side of the block, below and forward of the no. 1 exhaust port. The VIN derivative is a nine character stamping. The second character will be the year of the block. 8 = 1968, 0 = 1970, 4 = 1974, etc.

 

412753 is 4 bbl, 1973, with Turbo 400, 1974 all 455 except W30. My parts book is 74 edition so I don't know if this mfd was used after that.

 

the gasket company that im ordering from wants to know if the engine is 68-72 or 73-76. is this because the engines made before the EGR era have thicker cast blocks? or is it strictly an intake thing because of the changes made to the heads in 73 that might affect the valley pan gasket?

should i order a kit for a 68-72 because of my F block or order a 73-76 kit because of my later style J heads?

 

Well, FelPro does list two different gaskets, MS96004 for the early motors and MS96015 for the later ones. I don't know if these photos are accurate (and note that the one is flipped around from the other, but the only difference seems to be the drain hole in the very middle of the valley pan and an additional formed area next to it. Neither of these features will affect sealing of the gasket or fit in the block. Frankly, I suspect either one will be fine.

MS96004 (front is to the left):



MS96015 (front is to the right):

 

If this is a cobbled together engine... I would be concerned about which pistons does this have- low, or high compression?
Jim

 

In looking at these photos again, there IS a subtle difference. It's a little difficult to see since the two pictures are different orientations. The difference is the size of the driver's side exhaust crossover port opening. On the MS96015 the driver's side is on top. On the MS96004, the driver's side is on the bottom. Note that the crossover opening on the MS96015 is slightly larger. I don't know if this will effect sealing or not, but to be safe, get the gasket that matches the HEADS, not the block.