Hey thanks for the replies.
really good forum with interesting info.
I have found a olds 350 72a for sale that I thought about maybe the best choice?
I use the car daily, really nice car to ride in.
I pull no Especially heavy loads with it.
Glide around the most.
When I bought it I took diesel only to run it cheap
Now has learned a bit more about Olds diesel and it was perhaps not the best choice.

But the car is in good condition so it was worth it anyway.
Have learned a lot about olds and it is quite easy to be tinkered with them.
And can easily imagine to purchase and use a olds again.
What I have most trouble with now is to find the engine specification that I can use
at inspection need proof of motor power and evidence of similar engine power in the Chevy.
Your looks really good, good power in the engine
/markus