I finally aquired a 410 to place in the 68 F-250 I'm rebuilding from our son. My research so far tells me that it truely is a 410. The engineering number on the block is C6ME-A and according to Mustangtek this block is for a 390-428. If I were to consider boring the engine to build a 428 would it be possible? My concern is that the outside casting marks indicate it can be used for a 428 but the core used to cast the cylinder walls, are they different to accommodate the larger bore of the 428? Any Info will be appreciated.

Gear Up

 

4.05 to 4.13 requires--do the math--.080 over. Only if you have the block checked to make sure it will take that overbore on all cylinders will you know if it can be done on that block.

Then your block will be good for ONE run. Once it wears, it'll probably be done.

For what? Unless you do something else to the motor, you'll never feel the difference 18 or less cubes makes.

 

It's been said that many C6ME-A blocks exist that are in fact NOT 410's.

The only way to be sure is check the crank numbers, and of course, measure the bore. If the motor is still assembled, you can check the stroke with the wire or dowel trick.

 

If it is a 410, the flywheel or flexplate should have a counterweight on it.

I concur with the advise to not bore it any further than is needed to true up the cyl walls, even if the block is capable of going to 4.13. Once it has reached 4.13, they will rarely go any further. Granted, if the block is already 4.110 (.060 over 390/410) and needs a clean up bore, then you have nothing to lose if it is capable of going that extra .020.
For the little difference in total power output, I'd keep the block at it's smallest overbore possible, if it were mine. Pistons should be readily available in .020, .030, .040 and .060 over.

 

C6ME-A, I had a nice suprise when I purchased my 410 out of a 66 S-55. Same cast number, C6ME-A. When I got the heads off and measured the bore it was 4.13. Not knowing if it had been bored, I popped the soft plug on the side of the motor and found 428 cast into the water jacket. Might be a lot of 410's around that are 428's.