Richard,

Many thanks for your help. It looks like the majority of these would be similar blocks. If i stuck with 359 to 391 would work for maintaining the same bore. What do you think about companies like autoenginerebuilders online who have a 1968 rebuilt Cougar engine for around $1300? What should i expect to pay for a junkyard engine?

Years ago I recall that standard inspection was to look for a rod through the pan, a crowbar to see if you could turn it over and a look at the valves to see if they were still oily.

Robin