Engine numbers

[mike396]

I have 1969 SS convertible, 396 4-speed. The engine is a 325hp L-35. The partial vin is correct on the lower part of the block as well as the engine numbers on the front pad. My question is when the engine is sent out to the machine shop, if the block is decked and the engine numbers are removed will this effect the proof I need to prove originality? Or will the partial vin be all that is needed.
Thanks

[PACE&Z2869]

HELLO. I WOULD NOT DECK THAT ENGINE AT ALL UNLESS IT IS ABSOLUTALY REQUIRED!!  IF YOU ARE NOT GOING TO RACE THIS ENGINE IT SHOULD BE OK.  IF YOUR MACHINE SHOP SAYS IT MUST BE DECKED I WOULD GET ANOTHER OPINION.  I ASKED MY MACHINIST WHEN I HAD MY DZ 302 BLOCK DONE THAT IF I HAD TO DECK IT COULD HE DECK IT UP TO THE NUMBERS BUT NOT REMOVE THEM?  HE SAID THAT IT MIGHT BE POSSIBLE.  I ENDED UP NOT NEEDING TO DECK IT HOWEVER. DOING THE ABOVE WOULD LEAVE A SMALL STEP ON THE DECK,  PLUS YOU MUST MACHINE ENOUGH SO THE HEAD WILL SIT FLAT BUT THIS IS BETTER THAN NO NUMBERS AT ALL. DON'T LET YOUR MACHINIST TALK YOU IN TO RESTAMPING OR ANYTHING ELSE THAT YOU KNOW WILL REDUCE THE VALUE OF YOUR ENGINE OR CAR. MOST (NOT ALL)  MACHINIST DO RACE ENGINES AND DON'T APPRECIATE ORIGINALITY.  325 HP 396 IN A CONVERTABLE HUH?  PRETTY COOL!  GOOD LUCK.

[fiveforty]

If the block really need to be decked you can do it with a taper, not or barely touching the front pad and tapering down toward the rear. I would do whatever I had to do to preserve the #s.

[JohnZ]

Taper-decking is a BAD idea - screws up lots of important relationships. Most shops want to deck every block as a routine part of a rebuild, but if the deck doesn't vary more than .003" from dead flat, it'll work fine with composition head gaskets (but won't with production-type steel shim gaskets). 

[westonz28]

I have had two engines decked. All the machine shop had to do was finsh the area by hand and I got to keep the numbers. Just had to tell them before hand what I wanted.

[fiveforty]

If I had to preserve my DZ or JH block I would have no problem with a .0005 or .010 tapered  cut towards the rear of the block. Check a few deck heights from the factory next time you square up a block you might be surprised how much some vary from end to end. Remember these are high $ restorations not 1/4 mile racers.

[mike396]

Thanks for the help guys, Hopefully when I tear the motor down it will not need to be decked. If it does at least I have options.