I'm having my '79 360 engine rebuilt and ran into a problem with the heads. 1st the heads on my engine showed cracks around one or two valves then we found some cracks in the replacements. Is this a problem with this era engine?

 

could be from them overheating or not getting enough oil. I do know that the LA heads usually need to be rebuilt every 75,000 miles.

 

i never heard of that nor had a problem after 75,000. X my fingers!
whys that? valve guides?

ive seen a few cracked heads. crack between the exsaust and intake dont kn ow for sure what caused it. my guess is overheating

 

1966Sportfury is 110 % right ! they crack like a ford right between the valves. that is over heating and cooling off fast . The way I think that happens is the coolant doesn't travel far enough like to the heater core or is pluged or disconnected or cousing a bubble in the system . Or you block deck isn't true . Find a stright edge and check you block deck . maybe your intake has a slight leak .

 

Um your not buying old race cylinder's are you ? Where the race engine's use a steel shim gasket kit . becuase they dont seal and are not flexible . maybe your best bet is to buy new heads with 2.02 and 1.60 valves . like INDY or WORLD OR ELDERBROCK . with a macthing intake and card set up .