Originally Posted by 68390gt
after owning my '68 Mustang 390 GT fastback for 8 yrs, i recently developed a knock in the engine - I'm probably going to be pulling the engine to see if it a main or caps that are bad - having receipts for a complete overhaul of the engine in 1995, I started checking date codes, etc - i just found what i think is the block # on the lower right side of the block - D4TE - am i correct (& screwed) thinking this is a 1974 truck engine???
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.