Originally Posted by Shelby1
Yes that code is for a 74 truck engine, but that code is also on 360/390/& 410 blocks ,the only way to know what you have is to measure the stroke and in the case of the 410 the bore also. since you are going to pull the motor anyway ,when you pull the pan measure the stroke then.You will have people tell you to look at the crank for the casting # and that will tell you what you have but I hvae found crank's with the wrong # that have been reground to the right stroke. Point is you never know what you'll find when you open a motor up.
the stroke's on these motors are 360...3.5, 390(391)...3 7/8....410 same as the 390 plus larger bore.
hope this helps
Oh! if it is a 390(391) truck motor it has the strongest bottom end of all the FE blocks.
410 should be a 428 stroke (3.98 inch) with a 390 bore (4.05). One has to be careful as there is another 410 here on the MEL block, aside from "410" the FE and MEL share nothing in common the latter being a 4.2 bore by 3.7 stroke.
406 is 390 stroke (3.76) with a 4.13 bore
428 is a 3.98 stroke with a 406 bore
427 is a 390/406 stoke with a 4.23 bore.