this engine was given to me crank checks 4.oo stroke but these are the numbers on the block. d7t3 a3b and right under it is 9j25 what is this? also this motor was rebuild by a big engine builder here in S.C. and the guy bent all the push rods and broke the timing chain. I took the motor apart and can't find any damage other than a broken rocker arm bolt. what could have happened to bend all the push rods and no other damage than i stated. thanks for your help

 

The first number is the casting number. It indicates a 1977 casting. The last number is a specific date code. I think it means Janurary, June, or July 1979. These numbers will not tell you if it's a 351M or 400. If it has a 4.00 inch stroke, then it must be a 400.

If the rebuilder shaved the head or deck, then the stock pushrods might be too long, causing them to bend. If they used a high lift cam and didn't check for valve spring binding, the push rods could bend.

The solution is to get a pushrod length checker and verify the pushrod length before ordering new pushrods. Also check for valve spring binding.

 

The casting code is actually D7TE A3B which means it is a 1977 version casting however it was actually cast Sept 25, 1979. As Dan said it sounds to me like someone put a high lift cam in it and didn't change the stock valve springs which meant they went solid and bent the pushrods.