Difference in 250 oil pans and timing cover junctions

[bubbasimms]

Hello all,
I have what I thought were identical 250 six engines. I have one at the machine shop as we speak and I was collecting the best of the tins to clean and paint in preparation for putting the engine together. I noticed the oil pans and timing covers are different. One "set" has bolt holes where the pan and timing cover meet and one "set" does not. Can someone explain the difference to me? Seems the one with the extra bolt holes would seal better.

[D13]

There are 'early and 'late' sixes. They changed pan bolt counts, rear main seals, and the front belt spacings and a couple other details. I don't remeber if the timing pointer moved. And then the integral heads changed valve covers.. but that's another story.

The later ones are 'better', in that it takes longer for the inevitable rear main seal leak to start.

Key is, the tins needs to match each other. Also check and make sure what bolt pattern and size (front and rear pan bolts in particular) to insure you are all good.

[bubbasimms]

Thank.you.....looks like I'll also need to make sure I've got the right gasket set for the correct rear main seal. Hopefully the machine shop will order the correct parts