Stupid question , while taking inventory of parts ordered for my 455 + .030 build I checked my Mahle headgaskets part #55047 and the package label reads 4.200 x .040" . Looking on Jegs website no other Mahle headgasket for 455 listed , would this be the correct headgasket even though the bore is 4.155 ?

THX in advance

 

Head gasket bores are always larger than the cylinder bore, if that’s what you were wondering.

 

^^^THIS. If you had bored that 455 0.060, the bore would be 4.185, so 4.200 makes perfect sense. Just don't try to use it on a 403. (Hint, the stock bore on a 403 is 4.351)

 

Good gasket but they do require a certain finish on the deck and heads. Were those surfaced?

 

Yes the block was decked and the heads are new Pro comp .. Thanks for the responses ..