can anyone tell me if i have to take off the oil pan to change the timing chain on a 351m 1979 f250?????

 

Welcome to FTE maddog.
Thanks for joining us!

 

Yes, at least the front 4 bolts & loosen the others

 

so do i have to raise the engine like if i was changing the oil pan gasket?

 

i have never loosened or removed any pan bolts. i trim a little off the ends of the inside tabs that hold the pan end seal so that the cover can sneak back in. not too much, just the little corners. and i reuse the old end seal(if it's ok) because it is smooshed a little and goes in easy. test fit the cover before you put the seal on to see if it sneaks in ok. use a little rtv on the inside where you trimmed and on the end seal. i haven't had one leak yet...by the book you should drop the pan and reseal it too.